Aamulehti 236, 11.10.1924
Jo ammoisista ajoista on havaspyydysten mätänemistä koetettu estää erilaisilla menettelytavoilla, toisin sanoen on tahdottu hapaat ikäänkuin kyllästyttää. Säilytysaineita voimme erottaa kahdenlaisia: sellaisia, jotka peittävät langan tai sen yksityiset säikeet vedenpitävällä kalvolla, esim. liinaöljy, terva ja karboliini, ja sellaisia, jotka imeytyvät langan sisälle sekä sisältävät bakteereita tappavia aineita, kuten parkkihappo ja erilaiset metallisuolat.
Edellisiä voidaan käyttää pääasiassa karkeammista langoista valmistetuille pyydyksille, kuten nuotalle ja eräille sulkupyydyksille, rysille y.m.; sitävastoin ei silmillään vangitsevia pyydyksiä, kuten verkkoja, voida edullisesti värittää sellaisilla aineilla, jotka ympäröivät langan paksuntavalla kerroksella eli kalvolla ja niinollen jäykistävät sitä. Siksipä verkkojen väritykseen sovellutetaankin jälkimäinen menettelytapa, jolla säilytetään pyydykselle parempi kalastuskyky, se kun edelleen jättää langan hienoksi ja pehmeäksi.
Ennenkuin uusia verkkoja voidaan hyvällä tuloksella värittää, täytyy niistä useimmiten keittää rasva pois. Lanka on näet uutena rasvapitoista, joten väritys ilman edelläkäpää keittämistä ei tule kestäväksi. Keittäminen toimitetaan tavallisesti vedellä ja voidaan siihen työn jouduttamiseksi sekoittaa hiukan lipeää tai sammutettua kalkkia, noin 1 litra 100 litraan vettä. Keittämisen jälkeen kuivataan langat, ennenkuin ryhdytään niitä varsinaisesti värittämään.
On huomattu, että verkon kalastuskykyä voidaan melkoisesti parantaa, jos se väritetään kunkin vesistön laadun mukaisesti. Toisissa vesistöissä pyydystää ruskea verkko, muutamassa sininen, käytetäänpä joskus vihreitäkin verkkoja j.n.e. Voivatpa eri värivivahdukset samassakin järvessä antaa erilaisia tuloksia vuodenajoista riippuen.
Enemmän tai vähemmän ruskea väri saadaan verkolle seuraavalla vanhastaan tunnetulla ja yksinkertaisella tavalla. Pata täytetään ¾ vedellä ja sen jälkeen ääriään myöten kuusen ja männyn kävyillä tai käpyjen puutteessa hienonnetulla kuusen, koivun tai tammen kuorella. Tämän jälkeen keitos peitetään kannella ja saa kiehua 3—4 tuntia. Sitten sovitetaan väritettävät verkot kannelliseen saaviin ja kaadetaan siivilöity väriliuos kiehuvana verkkojen päälle, jonka jälkeen saavi peitetään huolellisesti kannella. Nyt annetaan verkkojen olla saavissa kannen alla, jos ne ovat uusia, 1—2 vuorokautta. On muuten huomattava, että väriliuosta tulee olla niin paljon, että se täydellisesti peittää saavissa olevat väritettävät langat.
Kun puuvillaverkot eivät värity niin helposti kuin liinaverkot, on niitä käsiteltävä useampaan kertaan ylläesitetyllä tavalla, jos niistä halutaan tummahkon ruskean värisiä. Jos sitävastoin väritettävänä on vanhoja verkkoja, joiden pelätään tulevan liian tummiksi, voidaan liiallista värittymistä estää siten, että verkot onnen värittämistä liotetaan vedessä ja sitten kosteina väritetään.
Kun kaikki mainitut ainekset sisältävät parkkialuetta, joka puhdistaa ja säilyttää langan hyvänä, voidaan tätä väritysmenettelyä paremman puutteessa suositella.
Kävyt, joita väritykseen käytetään, on paras koota kevätkesällä. Vanhoja ja lionneita käpyjä ei kan nata koota. Kuivassa ja ilmavassa paikassa talletettuna säilyttävät kävyt tarvittavan parkkialueen vuosikausia.
Yleisimpänä ja eniten käytettynä verkon väritysaineena tunnetaan kuitenkin "kateku". Tämä väriaine saadaan eräästä Itä-Indiassa kasvavasta akaasia-kasvista. Kaupoissa löytyy kateku puhtaana ja kovana aineena, jota voidaan käyttäessä liuottaa veteen.
Katekua käytetään värjäyksessä seuraavalla tavalla; 10 lankakiloa kohti otetaan 1 kg katekuväriä, 50 gr sinikiveä (kuparivithrilliä) ja, jos verkot ovat uusia ½ kg bresiljaa (lahoväriä) sekä niin paljon vettä kuin tarvitaan verkkojen täydelliseen peittämiseen väritysastiassa. Kateku ja bresilja pannaan kumpikin omaan, harvasta kankaasta tehtyyn pussiinsa, jotka pussit ripustetaan puikolla eli kepillä pataan värityksessä käytettävään veteen, kuitenkin niin, että pussit eivät satu padan pohjaan, sillä väriaine liukenee alaspäin. Sinikivi (vihtrilli) sekoitetaan veteen sellaisenaan ja käytetään sitä tummemman värin aikaansaamiseksi. Kun väriliuos on kiehunut noin ½ tuntia ja väritysaineet ovat hyvin liuenneet, kaadetaan se kuumana verkkojen päälle, jotka löysinä ovat lasketut väritysastiaan (mieluimmin puiseen). Kun liuos näin peittää täydellisesti väritettävät langat, peitetään astia ja annetaa verkkojen hautua siinä, kunnes ne ovat täydellisesti jäähtyneet. Tämän jälkeen nostetaan verkot liuoksesta, valuttamalla liikaliuos takaisin väritysastiaan. Ylijäänyt väritysaine voidaan näet sinänsä käyttää vanhojen, ennen väritettyjen verkkojen värittämiseen. Kun liikaliuos on hyvin valunut, levitetään verkot kuivamaan. Verkot eivät saa olla pitkää aikaa käyttämättöminä, sillä silloin väriaine polttaa ne hauraiksi ja kelpaamattomiksi. Viimeistään kahden päivän kuluttua on ne laskettava veteen likoamaan, ja vasta vuorokautta myöhemmin ovat ne täysin valmiit käytettäviksi.
Nykyään on kaupoissa saatavana useammankin laatuisia hyviä verkkovärejä m.m. Scheutzin verkkoväri ja S.O.K:n viime vuonna kauppaan laskema väri. Nämä värit käsittää kaksi eri ainesta nim. itse värin ja vahvistusaineen. Käyttämällä enemmän tai vähemmän väriä voidaan verkkojen väri sovittaa veden ja pohjan mukaan sinertävästä tummansiniseen. Tavallisesti sakotetaan kutakin lankakiloa kohden 100 cr. väriä 20 ltr;aan vettä. Kun väri on täydellisesti liuennut, upotetaan verkot siihen, joka sitten kuumennetaan ja saa hiljalleen kiehua noin tunnin ajan. Värjäyksen jälkeen kierretään verkot ja pannaan viipymättä, ilman huuhtelua, vahvistusaine liuokseen, joka valmistetaan siten, että kutakin lankakiloa kohden liuotetaan 100 gr valmistusainetta 20 ltr:an vettä. Tässä saavat verkot maata seuraavaan päivään, jolloin ne kierretään ja huuhtelematta levitetään kuivumaan. Jo käytettyjä värjäys- ja vahvistusaineliuoksia voidaan käyttää uudelleen. Näissä väreissä seuraa ohjeet mukana.
Seuraavaa Evon Kalastuskoeasemalla käyttämääni värjäystapaa voin myös suositella: Pataan, joka vetää 75—100 litraa, pannaan noin 50—60 litraa vettä ja 5—6 kg sianpuolukan varsia lehtineen sekä sama määrä tuoreita lepän kuoria. Seoksen annetaan kiehua 1½—2 tuntia, jonka kestäessä siihen pannaan 5 rkl. alunaa, tai enemmänkin, riippuen siitä tahdotaanko tummempaa väritystä. Kiehumisen jälkeen poistetaan sekä kuoret että varret liemestä ja liuokseen upotetaan niin monta verkkoa, että pata tulee täyteen. Sen jälkeen liuoksen taasen annetaan kiehua 1½ tuntia, jolloin verkot ovat täysin väriytyneet. Ne nostetaan pois liemestä ja levitetään kuivumaan. Tämä käyttöohje on edellytetty käytettäväksi uusille verkoille, jos värjättävänä on vanhoja verkkoja, voi väriainetta olla vähän vähemmän.
Sianpuolukka eli sianmarja on kuivilla kankailla ja somerikoilla kasvava varpukasvi, joka on hyvin puolukan näköinen, mutta eroaa siitä siinä, että lehdet ovat kärkipuolelta huomattavasti leveämmät, vastapuikeat (puolukap soikeat) punainen hedelmä jokseenkin mauton, jauhemainen. Kasvaessaan useimmin muodostaa pienempiä maitomaisia laikkuja.
Nuotta ja rysät jätetään usein kokonaan värittämättä, ehkä osittain siitä syystä, että nuotta toisinaan ollessaan pitemmät ajat kuivana on paremmin alttiina murtumiselle eli haurastumiselle, jos nim. hapaiden värittämiseen käytetään jäykistäviä aineita, kuten tervaa, liinaöljyä t.m.s.
Parhaana nuotan ja rysän väritysaineena tunnetaan nykyään karboliini. Mainittu aine tekee langan kestäväksi, tappaen bakteerit ja sienet paremmin kuin muut käytännössä olevat väritysaineet. Sitäpaitsi jättää se langan jäykistämättä pehmeäksi, jos vain värittäminen toimitetaan tarpeellisella huolellisuudella.
Väritettäessä käytetään karboliinia lämmitettynä, kaatamalla sitä väritysastiassa olevien hapaiden päälle siksi, kunnes ne ovat täydelleen peittyneet. Karboliinia käsiteltäessä on otettava huomioon, että aine ei ole ainoastaan hyvin väkevää, vaan myöskin erittäin tulenarkaa. Tästä johtuukin, että käsiä ja kasvoja on varjeltava joutumasta karboliinin yhteyteen, sekä että sen lämmittäminen värittämistä varten on toimitettava siten, että karboliiniastia upotetaan kiehuvalla vedellä täytettyyn astiaan. Hapaat pidetään liuoksessa noin 6—10 tuntia, jonka jälkeen ne levitetään kuivumaan vääntämällä ensin liika aines väritysastiaan. Karboliinia kuluu värittämiseen n. 1/10 langan painosta.
Pyydyksiä, jotka ovat karboliinilla väritettyjä, on varottava asettamasta suoranaiseen päivänpaisteeseen - kuivina - sillä siitä ne haurastuvat.
Rysiä ja martoja voidaan värittää samoin karboliinilla edellämainitulla tavalla, jolloin ne tulevat erinomaisen kestäviksi veden turmelevaa vaikutusta vastaan. Muuten sopii rysien ja mertojen värittämiseen käyttää liinaöljyä, varsinkin kun se tekee langan hyvin vahvaksi. Liinaöljyä käytettäessä on hankaluutena se, että se kuivaa hitaasti ja tahtoo jäädä langan pinnalle jäykistäväksi kerrokseksi. Tätä voitaneen estää talilla, paloöljyllä t.m.s.
Eräät kalastajat ovat hyväksi rysän väritysaineeksi havainneet seoksen, jossa on 1/5 tervaa ja 4/5 paloöljyä. Seos hämmennetään hyvin väritysastiassa ja rysän havas kastellaan huolellisesti tässä liuoksessa, jonka jälkeen se asetetaan väritysastian päälle kuivamaan siten, että liika aines valuu kuivaessa jälleen väritysastiaan toistamiseen käytettäväksi.
Usein käytetään pyydyksien kalastuskyvyn tehostajana sitä tapaa, että pyydykset savustetaan tervaksen tai katajan savulla, jolloin niistä kuolee bakteerit ja samalla jonkun verran värittyvät. Savenharmaissa vesissä tämä esim. verkolle on sopiva väri, mutta on työtä lisäävää sen johdosta, että savustus on usein uudistettava.
- T. P. Hakola.
Coloriasto on väriaiheisten tekstien (ja kuvien) verkkoarkisto
(Archive for colour themed articles and images)
INDEX: coloriasto.net
19.5.20
On the colors of spring flowers
The Living age 1952, 19.11.1881
From The Popular Science Review.
By Alfred W. Bennett, M.A., B. Sc., F.L. S.
Lectures on Botany, St. Thomas's Hospital.
Every one must have noticed the variations in the predominant color of our wild flowers as the season advances from spring to summer and autumn. In our hedge-banks the pure white of the larger stitchwort and "Jack-by-the-hedge" gives way to the bright blue of the speedwell, and then to the reddish purple of the black horehound and the various shades of the mallows. In our meadows the golden-yellow buttercups are gradually replaced by the pink of the sorrels and ragged robins, and then by the yellow ragwort and purple knapweed. Our riversides are gay in the early spring with the golden marsh-marigold, in the early summer with the yellow flag, in the later summer with the purple loosestrife. The bright scarlet of the poppies and the pimpernel only appears with the ripening corn. The blue campanulas, the bright-yellow St. John's wort, the purple heather, do not brighten the landscape till the summer is in its prime, when the green or inconspicuous flowers of the hazel, the elm, the oak, and nearly all our timber trees, have long since passed away. I do not know, however, that these facts have ever been tabulated, or any attempt made to reduce them to a general law; the present article is intended as a contribution to this object as far as our early spring flowers are concerned.
Under the title of early spring flowers I include all those named in Hooker's "Student's Flora" as beginning to blossom not later than April, with a very few additions which I think ought also to be included, at all events in our southern counties, viz., Ranunculus bulbosus, Lamium album, and Myosotis collina. As my object is to ascertain the prevalent color of the spring flora, I have confined the list to common plants, excluding those of less general distribution which might obviously introduce an element of error into the average. For this purpose I have taken as my guide the last edition of the "London Catalogue of British Plants," and have struck out all which do not bear at least as high a number as fifty. Though this mode of limitation is not altogether satisfactory — as plants of wide distribution may nevertheless not be common — it is, I think, the best available. In the limitation of species, I have followed Hooker's "Student's Flora." The classification of colors, where so many shades are represented, is not easy. I finally decided on arranging them under five heads, viz., (1) white, (2) green, (3) yellow, (4) red and pink, (5) blue and violet. Very slight shades of color, as in Anemone nemorosa, Cardamine pratensis, and Oxalis acetosella, are neglected. The sweet violet is placed under two heads. Finally, several large natural orders in which the flowers are very inconspicuous are entirely passed over, viz., the Amentiferæ, Juncaceæ, Gramineæ, Cyperaceæ, and Coniferæ.
Out of a total of sixty-four species, there are 26 white, amounting to 40.5 per cent; 9 green, or 14.1 per cent; 13 yellow, or 20.3 per cent; 5 red or pink, or 7.3 per cent; and 11 blue or violet, or 17.4 per cent. I have not been able to prepare a similar list of our common summer and autumn flowers; but even without this there are a few points which strike one at once. Firstly, there is the very great preponderance of white flowers, which is certainly not the case at any other time of the year. Yellow is also greatly in excess as compared with other seasons; and the number of red and pink flowers is extremely small. It is obvious that if the excluded natural orders named above were restored, the plants belonging to them having mostly inconspicuous green or brown flowers, while some have bright yellow anthers, the proportion of red and blue in particular would he greatly diminished. The common cuckoopint is reckoned a green flower, from the color of the spathe which encloses the whole inflorescence.
Before attempting to draw any conclusions from these figures, it may be useful to compare them with those relating to some other spring flora, say that of Switzerland. The difficulties in the way of any exact enumeration are here very great. The best materials at my hand are the two volumes already published of Schoth's "Alpine Plants;" but these include only two hundred species selected for a special purpose. Although not entirely satisfactory, such a list may yield some trustworthy results. I have here taken May, instead of April, as the latest early spring month; and have no data from which to exclude any species on account of their rarity.
Out of fifty species in this list (one A ndrocace chamajasme, being again reckoned twice over among the whites and pinks), 18, or 36 per cent. are white; 1, or 2 per cent. green; 10, or 20 per cent. red or pink; and 8, or 16 per cent. blue or violet.
Several points of contrast between these two lists will at once suggest themselves. The very small number of green flowers in the second may no doubt be due partly to the fact that Seboth's work includes a selection only of Alpine flowers suitable for cultivation. But this will hardly account for the other differences; the smaller proportion of white flowers, and especially the very much larger proportion — about three and a half times as many of ted and pink flowers, a fact which will be in accordance with every one's recollection of the early spring flora of Switzerland. Now let us see whether we can arrive at any general conclusions from these data.
* Dull. Soc. Bot. France, xxvi. (1879), p. 249.In the first place, it must be borne in mind that the two colors white and green stand on a different footing from all the rest, and may be regarded as, more cm, reedy speaking, an indication of the absence of color. The color of green petals is not due to a mixture of blue and yellow pigments, but to the presence of chlorophyll, the ordinary green coloring matter of leaves. The bright colors of petals are not usually assumed till immediately before their emergence from the bud; and not a few — as for example those of Cobæa scandens, are still green when they first open, acquiring their proper color only on full exposure to the light and warmth. A white flower again does not owe its color to a milk-white fluid in the cells of the petals. but to the presence of air. Seeing, therefore, that the bright-colored fluid pigments of petals are formed only under the influence of a sufficient supply of light and heat, the large proportion of green and white in our early spring flowers is easily accounted for. Then with regard to yellow, I find an exceedingly interesting observation by M. Flahaut* that "a solid, insoluble pigment, the xanthine of Frémy and Cloëz, is in the first place to be distinguished from all the soluble coloring matters, blue, yellow, red, and their mixtures, all of which are acted on very readily by reagents, and which are usually formed only in the epidermal cells." This xanthine Frémy states to occur always in "the form of clearly defined grains, occasionally in the epidermal, much more often in the deeper-lying cells, slowly soluble in alcohol and potassa. It is in all probability a modification of chlorophyll." The following is a list of the plants in which he has detected it: Ranunculus, Primula, Cheiranthusm Galeobdolon luteum, Doronium plantagineum, Alyssum saxatile, Cypripedium Calceolus, Azalea chinensis, Uvularia grandiflora, Eranthis hyemalis, Forsythia viridissima, Tussilago Farfara.
* Acta hort. Petrop. VI. ii., p. 279.
** Bull. Soc. Bot. France, xxvii. p. 103. It is worth noting that these are without exception early, and some of them very early, spring-flowering plants. The colors, therefore, which pre-eminently distinguish our summer and autumn flora, the red, pinks, blues, and some yellows (not due to xanthine, but to a soluble yellow pigment), are caused by the presence of substances which require both a strong light and a high temperature for their production, and Professor Batalin has shown this to be especially the case with the red coloring substance.* That the same species of flower frequently assumes a more intense color with increasing altitude in the Alps is a matter of ordinary notice, confirmed by the exact observations of M. Bonnier,** who states that this change is due to an actual increase in the amount of coloring matter in the cells. The difference already pointed out between the prevailing colors of the spring flora in England and in Switzerland, seems to me to be due to the same cause. Owing partly to the spring being a month later, partly to the more southern latitude, and consequent greater elevation of the sun, partly to the clearer air of a high altitude, the light which opens the earliest spring flowers is much stronger in Switzerland than in England, causing the appearance of those brilliant roses and pinks of the silenes, ericas, and primulas, and blues of the gentianas, soldanellas, and phyteumas, with which we have, with the exception of our bluebells, scarcely anything to compare in our spring flora. In the list given above, the most striking feature of the early spring flora of Switzerland is seen to be the very large ingredient of red and pink: but I believe a more complete analysis would show an almost equal preponderance of blue.
* Alpenblumen; ihre Befruchtung durch insekten and ihre Anpassungen an dieselben. Leipzig, 1881.
** See Nature, 1880, vol. xxi., No. 535.I have not in this paper touched on the interesting subject of the adaptation of the various colors of flowers to fertilization by insect agency, about which much has been, and very much might be, written. As Hermann Mü11er points out in his most recent publication,* changes in the color or form of flowers which are serviceable to them for purposes of fertilization, can only be the result of external physical causes, and must be perpetuated by natural selection acting on heredity. This writer, who has made the subject specially his own, fully confirms the statement of the greater brightness of color of the flora of the Alps as compared with that of the plains, a result not only of the occurrence of brighter-flowered species, but also of the greater intensity of color in the same species. This he attributes to the greater transparency of the mountain air, and consequent more intense light, an explanation which is confirmed by the experiments of Siemens with the electric light.** The observations of Muller with regard to the prevalent colors of Alpine flowers are completely in accord with those stated above, viz., the comparative scarcity of white, and the remarkable prevalence of red and blue flowers; he further states that those flowers only are red or blue which are visited chiefly or exclusively by bees and "hover-flies" (Syrphidæ). It would be interesting to compare this fact with the time of year at which these groups of insects are most abundant.
* Proceedings of Edinburgh Botanical Society, 1876. The conclusions arrived at in this paper are somewhat at variance with those of Mr. Buchan,* who states that the blues, on the average, flower considerably the earliest; then, in order, the whites, purples, and lastly the yellows and reds. It is possible that the discrepancy may arise from Mr. Buchan having based his result on the entire English flora, while I have taken only the commonest flowers.
From The Popular Science Review.
By Alfred W. Bennett, M.A., B. Sc., F.L. S.
Lectures on Botany, St. Thomas's Hospital.
Every one must have noticed the variations in the predominant color of our wild flowers as the season advances from spring to summer and autumn. In our hedge-banks the pure white of the larger stitchwort and "Jack-by-the-hedge" gives way to the bright blue of the speedwell, and then to the reddish purple of the black horehound and the various shades of the mallows. In our meadows the golden-yellow buttercups are gradually replaced by the pink of the sorrels and ragged robins, and then by the yellow ragwort and purple knapweed. Our riversides are gay in the early spring with the golden marsh-marigold, in the early summer with the yellow flag, in the later summer with the purple loosestrife. The bright scarlet of the poppies and the pimpernel only appears with the ripening corn. The blue campanulas, the bright-yellow St. John's wort, the purple heather, do not brighten the landscape till the summer is in its prime, when the green or inconspicuous flowers of the hazel, the elm, the oak, and nearly all our timber trees, have long since passed away. I do not know, however, that these facts have ever been tabulated, or any attempt made to reduce them to a general law; the present article is intended as a contribution to this object as far as our early spring flowers are concerned.
Under the title of early spring flowers I include all those named in Hooker's "Student's Flora" as beginning to blossom not later than April, with a very few additions which I think ought also to be included, at all events in our southern counties, viz., Ranunculus bulbosus, Lamium album, and Myosotis collina. As my object is to ascertain the prevalent color of the spring flora, I have confined the list to common plants, excluding those of less general distribution which might obviously introduce an element of error into the average. For this purpose I have taken as my guide the last edition of the "London Catalogue of British Plants," and have struck out all which do not bear at least as high a number as fifty. Though this mode of limitation is not altogether satisfactory — as plants of wide distribution may nevertheless not be common — it is, I think, the best available. In the limitation of species, I have followed Hooker's "Student's Flora." The classification of colors, where so many shades are represented, is not easy. I finally decided on arranging them under five heads, viz., (1) white, (2) green, (3) yellow, (4) red and pink, (5) blue and violet. Very slight shades of color, as in Anemone nemorosa, Cardamine pratensis, and Oxalis acetosella, are neglected. The sweet violet is placed under two heads. Finally, several large natural orders in which the flowers are very inconspicuous are entirely passed over, viz., the Amentiferæ, Juncaceæ, Gramineæ, Cyperaceæ, and Coniferæ.
Out of a total of sixty-four species, there are 26 white, amounting to 40.5 per cent; 9 green, or 14.1 per cent; 13 yellow, or 20.3 per cent; 5 red or pink, or 7.3 per cent; and 11 blue or violet, or 17.4 per cent. I have not been able to prepare a similar list of our common summer and autumn flowers; but even without this there are a few points which strike one at once. Firstly, there is the very great preponderance of white flowers, which is certainly not the case at any other time of the year. Yellow is also greatly in excess as compared with other seasons; and the number of red and pink flowers is extremely small. It is obvious that if the excluded natural orders named above were restored, the plants belonging to them having mostly inconspicuous green or brown flowers, while some have bright yellow anthers, the proportion of red and blue in particular would he greatly diminished. The common cuckoopint is reckoned a green flower, from the color of the spathe which encloses the whole inflorescence.
Before attempting to draw any conclusions from these figures, it may be useful to compare them with those relating to some other spring flora, say that of Switzerland. The difficulties in the way of any exact enumeration are here very great. The best materials at my hand are the two volumes already published of Schoth's "Alpine Plants;" but these include only two hundred species selected for a special purpose. Although not entirely satisfactory, such a list may yield some trustworthy results. I have here taken May, instead of April, as the latest early spring month; and have no data from which to exclude any species on account of their rarity.
Out of fifty species in this list (one A ndrocace chamajasme, being again reckoned twice over among the whites and pinks), 18, or 36 per cent. are white; 1, or 2 per cent. green; 10, or 20 per cent. red or pink; and 8, or 16 per cent. blue or violet.
Several points of contrast between these two lists will at once suggest themselves. The very small number of green flowers in the second may no doubt be due partly to the fact that Seboth's work includes a selection only of Alpine flowers suitable for cultivation. But this will hardly account for the other differences; the smaller proportion of white flowers, and especially the very much larger proportion — about three and a half times as many of ted and pink flowers, a fact which will be in accordance with every one's recollection of the early spring flora of Switzerland. Now let us see whether we can arrive at any general conclusions from these data.
* Dull. Soc. Bot. France, xxvi. (1879), p. 249.In the first place, it must be borne in mind that the two colors white and green stand on a different footing from all the rest, and may be regarded as, more cm, reedy speaking, an indication of the absence of color. The color of green petals is not due to a mixture of blue and yellow pigments, but to the presence of chlorophyll, the ordinary green coloring matter of leaves. The bright colors of petals are not usually assumed till immediately before their emergence from the bud; and not a few — as for example those of Cobæa scandens, are still green when they first open, acquiring their proper color only on full exposure to the light and warmth. A white flower again does not owe its color to a milk-white fluid in the cells of the petals. but to the presence of air. Seeing, therefore, that the bright-colored fluid pigments of petals are formed only under the influence of a sufficient supply of light and heat, the large proportion of green and white in our early spring flowers is easily accounted for. Then with regard to yellow, I find an exceedingly interesting observation by M. Flahaut* that "a solid, insoluble pigment, the xanthine of Frémy and Cloëz, is in the first place to be distinguished from all the soluble coloring matters, blue, yellow, red, and their mixtures, all of which are acted on very readily by reagents, and which are usually formed only in the epidermal cells." This xanthine Frémy states to occur always in "the form of clearly defined grains, occasionally in the epidermal, much more often in the deeper-lying cells, slowly soluble in alcohol and potassa. It is in all probability a modification of chlorophyll." The following is a list of the plants in which he has detected it: Ranunculus, Primula, Cheiranthusm Galeobdolon luteum, Doronium plantagineum, Alyssum saxatile, Cypripedium Calceolus, Azalea chinensis, Uvularia grandiflora, Eranthis hyemalis, Forsythia viridissima, Tussilago Farfara.
* Acta hort. Petrop. VI. ii., p. 279.
** Bull. Soc. Bot. France, xxvii. p. 103. It is worth noting that these are without exception early, and some of them very early, spring-flowering plants. The colors, therefore, which pre-eminently distinguish our summer and autumn flora, the red, pinks, blues, and some yellows (not due to xanthine, but to a soluble yellow pigment), are caused by the presence of substances which require both a strong light and a high temperature for their production, and Professor Batalin has shown this to be especially the case with the red coloring substance.* That the same species of flower frequently assumes a more intense color with increasing altitude in the Alps is a matter of ordinary notice, confirmed by the exact observations of M. Bonnier,** who states that this change is due to an actual increase in the amount of coloring matter in the cells. The difference already pointed out between the prevailing colors of the spring flora in England and in Switzerland, seems to me to be due to the same cause. Owing partly to the spring being a month later, partly to the more southern latitude, and consequent greater elevation of the sun, partly to the clearer air of a high altitude, the light which opens the earliest spring flowers is much stronger in Switzerland than in England, causing the appearance of those brilliant roses and pinks of the silenes, ericas, and primulas, and blues of the gentianas, soldanellas, and phyteumas, with which we have, with the exception of our bluebells, scarcely anything to compare in our spring flora. In the list given above, the most striking feature of the early spring flora of Switzerland is seen to be the very large ingredient of red and pink: but I believe a more complete analysis would show an almost equal preponderance of blue.
* Alpenblumen; ihre Befruchtung durch insekten and ihre Anpassungen an dieselben. Leipzig, 1881.
** See Nature, 1880, vol. xxi., No. 535.I have not in this paper touched on the interesting subject of the adaptation of the various colors of flowers to fertilization by insect agency, about which much has been, and very much might be, written. As Hermann Mü11er points out in his most recent publication,* changes in the color or form of flowers which are serviceable to them for purposes of fertilization, can only be the result of external physical causes, and must be perpetuated by natural selection acting on heredity. This writer, who has made the subject specially his own, fully confirms the statement of the greater brightness of color of the flora of the Alps as compared with that of the plains, a result not only of the occurrence of brighter-flowered species, but also of the greater intensity of color in the same species. This he attributes to the greater transparency of the mountain air, and consequent more intense light, an explanation which is confirmed by the experiments of Siemens with the electric light.** The observations of Muller with regard to the prevalent colors of Alpine flowers are completely in accord with those stated above, viz., the comparative scarcity of white, and the remarkable prevalence of red and blue flowers; he further states that those flowers only are red or blue which are visited chiefly or exclusively by bees and "hover-flies" (Syrphidæ). It would be interesting to compare this fact with the time of year at which these groups of insects are most abundant.
* Proceedings of Edinburgh Botanical Society, 1876. The conclusions arrived at in this paper are somewhat at variance with those of Mr. Buchan,* who states that the blues, on the average, flower considerably the earliest; then, in order, the whites, purples, and lastly the yellows and reds. It is possible that the discrepancy may arise from Mr. Buchan having based his result on the entire English flora, while I have taken only the commonest flowers.
Om färger och kläder
Arbetarbladet 75, 3.7.1929
..skriver Mary Siljander i sin bok "Modern skönhetsvård":
Äldre damer böra ej kläda sig i svart såsom passande för deras ålder. Svart framhäver det gula och gråbleka i huden, gör alla rynkor, veck och skuggor djupare. Endast då ansiktet är ljust och fetlagt samt håret mycket mörkt, är svart passande. Men om ansiktsfärgen är blek, bör man undvika den svarta färgen, ty den nedsätter hyns klarhet och i allmänhet ser man äldre ut i svart. Feta damer taga sig smärtare och ungdomligare ut i mörka färger, helst i randiga, men ej rutiga tyger, ty de senare skänka varken värdighet eller behag.
Om äldre damer bibehållit sin ungdomliga figur, göra sig milda, fina "döda färger" (des teintes mortes) utmärkt, t. ex, krämfärg, lavendel, rengrått.
Ovanligt mörka damer kunna använda rika färger. För ljus hy passar måttligt ljust och över huvud taget ljusa schatteringar.
Till gulbrun hy bör vitt undvikas, ty den vita färgen gör att hyn verkar oren. Den som har blågul hy och svart hår kan skatta sig lycklig, ty denna typ kan välja färger med rätt stor frihet, t.o.m. rött, grönt och orange.
Den rödblonda med pärlemorby bör undvika rött, grönt och orange.
Till frisk, röd teint är blått i alla nyanser att föredraga och t.o.m. svart kan rekommenderas.
Den grå typen bör undvika rosa samt orange, de mest klädsamma färgerna äro de i blågrönt stötande.
Med avseende på valet av klädedräkt bör varje kvinnas mål vara att klä sig så fördelaktigt som möjligt. Dräkten är till för kvinnans skull och icke tvärtom, den bör alltid vara individuell och på samma gång vittna om ens smak ocn uppfinningsrikedom. Den skall dölja och mildra möjligen förefintliga ofullkomligheter; skönhet, grace och värdighet ger den ej, men framhåller med fördel det som finnes. Att blint följa modets nycker verkar löjligt, ty vad som kan vara klädsamt och vackert för en, kan vara mycket missklädande för en annan.
I promenaddräkten äro hatt, handskar och skodon det viktigaste. Det är likgiltigt av vad ens hatt är gjord, blott den är klädsam och sitter på huvudet såsom den bör. Håret skall taga sig fördelaktigt ut under hatten, som skall kläda ansiktet och harmoniera med hela frisyren.
Damer med liten haka borde icke gömma sig under en bredskyggig hatt, utan i stället bära en liten, som passar till huvudets form. En lång dam bör ej bära höga hattar. Den som har ett start ansikte, kan bära en bred, stor hatt. Den som har mycket tjocka läppar, bör ej bära hatten dragen lågt ned över ögonbrynen. Det är säkrare att bära en enkel hatt än en illa beklädd sådan.
Handskarna böra vara rena och hela samt väljas efter årstid och tillfälle.
Skodon. Ett par illa valda skor kan förstöra den elegantaste toalett, genom att vara elegant om fötterna hjälper man upp de enklaste kläder. Till promenad passa ej tygskor, utan kängor. Låga, urringade skor passa ej till skräddarsydd dräkt. Till en elegant kostym är det naturligtvis vackrast alt begagna skor av mocka eller chevreau.
Om vintern är det tämligen oskönt att traska, omkring med de åbäkliga yllerkängorna och genomskinliga strumpor. De fula ytterkängorna äro ursprungligen i sitt hemland ämnade för slädåkning; i vårt klimat äro de nog på sin plats, men icke såsom promenadskodor. - Varma strumpor med dito kängar äro både vackra och hälsosamma, gummiskor skydda för väta. Man bör gå klädd efter årstiden och klimatets fordringar.
..skriver Mary Siljander i sin bok "Modern skönhetsvård":
Äldre damer böra ej kläda sig i svart såsom passande för deras ålder. Svart framhäver det gula och gråbleka i huden, gör alla rynkor, veck och skuggor djupare. Endast då ansiktet är ljust och fetlagt samt håret mycket mörkt, är svart passande. Men om ansiktsfärgen är blek, bör man undvika den svarta färgen, ty den nedsätter hyns klarhet och i allmänhet ser man äldre ut i svart. Feta damer taga sig smärtare och ungdomligare ut i mörka färger, helst i randiga, men ej rutiga tyger, ty de senare skänka varken värdighet eller behag.
Om äldre damer bibehållit sin ungdomliga figur, göra sig milda, fina "döda färger" (des teintes mortes) utmärkt, t. ex, krämfärg, lavendel, rengrått.
Ovanligt mörka damer kunna använda rika färger. För ljus hy passar måttligt ljust och över huvud taget ljusa schatteringar.
Till gulbrun hy bör vitt undvikas, ty den vita färgen gör att hyn verkar oren. Den som har blågul hy och svart hår kan skatta sig lycklig, ty denna typ kan välja färger med rätt stor frihet, t.o.m. rött, grönt och orange.
Den rödblonda med pärlemorby bör undvika rött, grönt och orange.
Till frisk, röd teint är blått i alla nyanser att föredraga och t.o.m. svart kan rekommenderas.
Den grå typen bör undvika rosa samt orange, de mest klädsamma färgerna äro de i blågrönt stötande.
Med avseende på valet av klädedräkt bör varje kvinnas mål vara att klä sig så fördelaktigt som möjligt. Dräkten är till för kvinnans skull och icke tvärtom, den bör alltid vara individuell och på samma gång vittna om ens smak ocn uppfinningsrikedom. Den skall dölja och mildra möjligen förefintliga ofullkomligheter; skönhet, grace och värdighet ger den ej, men framhåller med fördel det som finnes. Att blint följa modets nycker verkar löjligt, ty vad som kan vara klädsamt och vackert för en, kan vara mycket missklädande för en annan.
I promenaddräkten äro hatt, handskar och skodon det viktigaste. Det är likgiltigt av vad ens hatt är gjord, blott den är klädsam och sitter på huvudet såsom den bör. Håret skall taga sig fördelaktigt ut under hatten, som skall kläda ansiktet och harmoniera med hela frisyren.
Damer med liten haka borde icke gömma sig under en bredskyggig hatt, utan i stället bära en liten, som passar till huvudets form. En lång dam bör ej bära höga hattar. Den som har ett start ansikte, kan bära en bred, stor hatt. Den som har mycket tjocka läppar, bör ej bära hatten dragen lågt ned över ögonbrynen. Det är säkrare att bära en enkel hatt än en illa beklädd sådan.
Handskarna böra vara rena och hela samt väljas efter årstid och tillfälle.
Skodon. Ett par illa valda skor kan förstöra den elegantaste toalett, genom att vara elegant om fötterna hjälper man upp de enklaste kläder. Till promenad passa ej tygskor, utan kängor. Låga, urringade skor passa ej till skräddarsydd dräkt. Till en elegant kostym är det naturligtvis vackrast alt begagna skor av mocka eller chevreau.
Om vintern är det tämligen oskönt att traska, omkring med de åbäkliga yllerkängorna och genomskinliga strumpor. De fula ytterkängorna äro ursprungligen i sitt hemland ämnade för slädåkning; i vårt klimat äro de nog på sin plats, men icke såsom promenadskodor. - Varma strumpor med dito kängar äro både vackra och hälsosamma, gummiskor skydda för väta. Man bör gå klädd efter årstiden och klimatets fordringar.
Astronomical and Meteorological Phenomena. Magnificent Aurora in February.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)There was a magnificent display of Aurora Borealis, on the evening of Sunday, Feb. 20, 1848: from numerous descriptions, we find selected, in the Athenæum, the following letter of Mr. Temple Chevallier. — "In the course of a fine display of Aurora Borealis at Durham, on the 20th of February, an auroral arch was observed of a very definite character. At 8h. 16m., Greenwich mean time, an arch of bright light, having a uniform breadth of about 2°, suddenly arose near the horizon in the N.E., and instantly spread across the whole sky. It passed a little eastward and southward of the stars of the Great Bear, directly across Capella, and a little west of the Pleiades. From these data it appears that the direction of the arch was very nearly that of a vertical circle, passing over the zenith of Durham, and, as usual, very nearly at right angles to the magnetic meridian. The arch was not traced to its western termination. Its duration was less than a minute. It is to be hoped that observations may have been made of the same arch in other places, so that its height above the earth's surface may be calculated. The barometer was remarkably low at the time, 28.421 inches; and the thermometer 39°5. The place of observation was 247 feet above the level of the sea. The latitude of Durham is 54°46’ 6", and its longitude 6' 18" west of Greenwich.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)There was a magnificent display of Aurora Borealis, on the evening of Sunday, Feb. 20, 1848: from numerous descriptions, we find selected, in the Athenæum, the following letter of Mr. Temple Chevallier. — "In the course of a fine display of Aurora Borealis at Durham, on the 20th of February, an auroral arch was observed of a very definite character. At 8h. 16m., Greenwich mean time, an arch of bright light, having a uniform breadth of about 2°, suddenly arose near the horizon in the N.E., and instantly spread across the whole sky. It passed a little eastward and southward of the stars of the Great Bear, directly across Capella, and a little west of the Pleiades. From these data it appears that the direction of the arch was very nearly that of a vertical circle, passing over the zenith of Durham, and, as usual, very nearly at right angles to the magnetic meridian. The arch was not traced to its western termination. Its duration was less than a minute. It is to be hoped that observations may have been made of the same arch in other places, so that its height above the earth's surface may be calculated. The barometer was remarkably low at the time, 28.421 inches; and the thermometer 39°5. The place of observation was 247 feet above the level of the sea. The latitude of Durham is 54°46’ 6", and its longitude 6' 18" west of Greenwich.
Astronomical and Meteorological Phenomena. Lunar Rainbow.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)
--
* For example, colours are not distinguishable in the prismatic spectrum formed by the light of putrescent shell-fish, or rotten wood.Sir John Herschel has communicated to the Athenæum, No. 1099, the following: —
Collingwood, Nov. 13.
Yesterday evening, at 6h. 40m. P.M., I had the gratification of witnessing, for the first time, the rare and beautiful phenomenon of a lunar rainbow in all its perfection. The moon (full on the 11th at 1h.30m. A.M.) was near the eastern horizon, shining brilliantly through a considerable clear opening in the otherwise generally and densely clouded sky. A light, drizzling, and very uniform rain was falling with a gentle wind from the N.E., The arch, very nearly a semi-circle, was perfect in every part — apparently much better defined and somewhat narrower than the solar rainbow (circumstances easily accounted for). Its span also appeared somewhat less; which of course was only an illusion. Though much brighter than I could have expected a lunar rainbow to appear (the effect, no doubt, of the very dark background of cloud against which it was projected), it exhibited scarcely any colour: barely enough to assure the spectators that the order of colour was as in the solar bow — a faint ruddy tinge being sensible on the outer, and a still fainter bluish hue on the inner side: affording a striking illustration of that singular law in the physiology of vision, that the perception of colour is not developed unless under a certain amount of the stimulus of light.*
Not only was the primary bow thus fully developed: the exterior or secondary rainbow was also visible; not indeed conspicuously, so as to attract attention -looked for, but quite unequivocally, and at its proper distance from the -rimary. To become sensible of its existence it was necessary to keep the eye wandering. Neither were traces wanting of the supernumerary arcs which form so conspicuous an appendage to the inner edge of the solar rainbow in certain contingencies. They were indicated by a perceptible streakiness fringing the internal border of the arc, though to say whether more than one streak existed was not possible.
The southern leg of this fine arch was evidently formed within a few hundred yards of our station; as, on ascending to the roof of my dwelling-house, it was seen on the hither side of some trees at that distance. When first seen it was perfect, and continued so for six or eight minutes — when clouds obscuring the moon put an end to it. I will only add further that the impression produced by the spectacle was of that peculiar, solemn, and unearthly kind which, once experienced, remains ever after ineffaceable. — I remain, &c.
- J. F. W. Herschel
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)
--
* For example, colours are not distinguishable in the prismatic spectrum formed by the light of putrescent shell-fish, or rotten wood.Sir John Herschel has communicated to the Athenæum, No. 1099, the following: —
Collingwood, Nov. 13.
Yesterday evening, at 6h. 40m. P.M., I had the gratification of witnessing, for the first time, the rare and beautiful phenomenon of a lunar rainbow in all its perfection. The moon (full on the 11th at 1h.30m. A.M.) was near the eastern horizon, shining brilliantly through a considerable clear opening in the otherwise generally and densely clouded sky. A light, drizzling, and very uniform rain was falling with a gentle wind from the N.E., The arch, very nearly a semi-circle, was perfect in every part — apparently much better defined and somewhat narrower than the solar rainbow (circumstances easily accounted for). Its span also appeared somewhat less; which of course was only an illusion. Though much brighter than I could have expected a lunar rainbow to appear (the effect, no doubt, of the very dark background of cloud against which it was projected), it exhibited scarcely any colour: barely enough to assure the spectators that the order of colour was as in the solar bow — a faint ruddy tinge being sensible on the outer, and a still fainter bluish hue on the inner side: affording a striking illustration of that singular law in the physiology of vision, that the perception of colour is not developed unless under a certain amount of the stimulus of light.*
Not only was the primary bow thus fully developed: the exterior or secondary rainbow was also visible; not indeed conspicuously, so as to attract attention -looked for, but quite unequivocally, and at its proper distance from the -rimary. To become sensible of its existence it was necessary to keep the eye wandering. Neither were traces wanting of the supernumerary arcs which form so conspicuous an appendage to the inner edge of the solar rainbow in certain contingencies. They were indicated by a perceptible streakiness fringing the internal border of the arc, though to say whether more than one streak existed was not possible.
The southern leg of this fine arch was evidently formed within a few hundred yards of our station; as, on ascending to the roof of my dwelling-house, it was seen on the hither side of some trees at that distance. When first seen it was perfect, and continued so for six or eight minutes — when clouds obscuring the moon put an end to it. I will only add further that the impression produced by the spectacle was of that peculiar, solemn, and unearthly kind which, once experienced, remains ever after ineffaceable. — I remain, &c.
- J. F. W. Herschel
Geology. Artificial Colours in Agate.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)
--
* Mr. Hamilton believes that not a few of the agates which have come down from ancient times have been thus treated.Tar change of Colour produced Artificially in the Agates by the workers in them at Oberstein, an art learned from the Italians, is of much interest mineralogically, since it shows the very different porosity of different layers in the agates, the least porous bands not being necessarily the nearest to the centre, but dispersed irregularly through the mass. To this porosity Mr. Hamilton calls attention, citing the researches of M. Noeggerath, who states, that in some layers the minute hollows can be seen by means of a magnifying glass; that, while some are round, others are long, and that they sometimes run into one another. These hollows, Mr. Hamilton considers, may form interstices between the radiating crystals. By immersion for some time in honey and water or olive oil, so that the pores of the agate become more or less filled with a substance to be carbonised, a subsequent soaking of the stone in sulphuric add produces a difference in the tints of the agate according to the porosity of the layers, the most porous becoming black, while the least porous remain white or uncoloured. By immersion in a solution of sulphate of iron, and a subsequent heating of the agate, a cornelian red is in like manner obtained for the most porous layers, the iron being converted into a peroxide, while the least porous layers continue unchanged in colour.* It would be out of place further to dwell upon the infiltration of mineral matter in solution into the isolated cavities of rocks. The mode in which the various minerals occur is highly interesting, as also their connection with the matter filling veins and fissures in adjoining parts of the same or adjacent rocks, as, for example, the filling of the fissures in the red conglomerate by the same kind of siliceous matter which entered into the cavities of the igneous rocks of Idal, the layers having, in both cases, adjusted themselves to the surfaces on which they were accumulated. — Sir Henry T. De la Beche's Anniversary Address to the Geological Society.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)
--
* Mr. Hamilton believes that not a few of the agates which have come down from ancient times have been thus treated.Tar change of Colour produced Artificially in the Agates by the workers in them at Oberstein, an art learned from the Italians, is of much interest mineralogically, since it shows the very different porosity of different layers in the agates, the least porous bands not being necessarily the nearest to the centre, but dispersed irregularly through the mass. To this porosity Mr. Hamilton calls attention, citing the researches of M. Noeggerath, who states, that in some layers the minute hollows can be seen by means of a magnifying glass; that, while some are round, others are long, and that they sometimes run into one another. These hollows, Mr. Hamilton considers, may form interstices between the radiating crystals. By immersion for some time in honey and water or olive oil, so that the pores of the agate become more or less filled with a substance to be carbonised, a subsequent soaking of the stone in sulphuric add produces a difference in the tints of the agate according to the porosity of the layers, the most porous becoming black, while the least porous remain white or uncoloured. By immersion in a solution of sulphate of iron, and a subsequent heating of the agate, a cornelian red is in like manner obtained for the most porous layers, the iron being converted into a peroxide, while the least porous layers continue unchanged in colour.* It would be out of place further to dwell upon the infiltration of mineral matter in solution into the isolated cavities of rocks. The mode in which the various minerals occur is highly interesting, as also their connection with the matter filling veins and fissures in adjoining parts of the same or adjacent rocks, as, for example, the filling of the fissures in the red conglomerate by the same kind of siliceous matter which entered into the cavities of the igneous rocks of Idal, the layers having, in both cases, adjusted themselves to the surfaces on which they were accumulated. — Sir Henry T. De la Beche's Anniversary Address to the Geological Society.
Geology. Lapis-Lazuli.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)The Petersburgh Academy of Sciences has published the following particulars relative to Lapis-lazuli and Mica: "Both these minerals are found in the vicinity of Lake Baikal, especially in the river Hindianka, and in all the rivers which fall from Mount Khamardaban. Mineralogists have not, however, yet succeeded in finding the flow of the lapis-lazuli, notwithstanding the minute researches which have been made in divers points of the localities. Mr. Moor, the mineralogist, who spent two summers on the banks of the Hindianka, succeeded only in discovering the flow of glaucolithe, or calcareous blue spath, and every attempt since made to ascertain the place of the formation of the lapis-lazuli has been unsuccessful. The natives affirm that this precious stone is met with after the heavy rains have washed down the pebbles found in the beds of the rivers. With regard to mica, it is found in great abundance in the neighbourhood of Hindianka, even with the ground, in the form of not very thick flakes, lying upon a bed of soft clay, as if it had been deposited upon it. The inhabitants frequently resort to these places to carry off the mica, which they put into their window-frames in place of glass.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)The Petersburgh Academy of Sciences has published the following particulars relative to Lapis-lazuli and Mica: "Both these minerals are found in the vicinity of Lake Baikal, especially in the river Hindianka, and in all the rivers which fall from Mount Khamardaban. Mineralogists have not, however, yet succeeded in finding the flow of the lapis-lazuli, notwithstanding the minute researches which have been made in divers points of the localities. Mr. Moor, the mineralogist, who spent two summers on the banks of the Hindianka, succeeded only in discovering the flow of glaucolithe, or calcareous blue spath, and every attempt since made to ascertain the place of the formation of the lapis-lazuli has been unsuccessful. The natives affirm that this precious stone is met with after the heavy rains have washed down the pebbles found in the beds of the rivers. With regard to mica, it is found in great abundance in the neighbourhood of Hindianka, even with the ground, in the form of not very thick flakes, lying upon a bed of soft clay, as if it had been deposited upon it. The inhabitants frequently resort to these places to carry off the mica, which they put into their window-frames in place of glass.
Natural history. Zoology. Luminous Spectra on the Retina.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
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MDCCCXLIX (1849)A paper has been read to the British Association, "On the Luminous Spectra exerted by Pressure on the Retina, and their Application to the Diagnosis of the Affections of the Retina and its Appendages," by Dr. A. Waller. These observations relate to the luminous spectra which appear in the field of vision when the eyeball is compressed, or when the head has received a sharp blow, and in various other circumstances. After having described the discoveries of Sir Isaac Newton and others, the author goes on to relate his own observations, and finds that these spectra vary according to the part of the eyeball which is compressed. If compressed at the upper part they appear to be most bright, and consist of several concentric rings alternately bright and dark. He shows that these spectra may be employed with great advantage as a means of discriminating the diseases of the retina and optic nerve from those which affect the crystalline lens, the iris, and the other parts in front of the retina. In amaurosis, glaucoma, and other affections of the nervous parts, the spectra are found to become more faint in proportion as the nervous powers are injured, and are entirely absent when the visual powers are more deeply impaired. On the other hand, in those numerous affections of the eye where the rays of light can no longer form their images on the retina on account of the opacity of the parts which they have to traverse, the ocular spectra are found to be unimpaired in their brightness. The author cited numerous cases in confirmation of this statement.
— Athenæum, No. 1087.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)A paper has been read to the British Association, "On the Luminous Spectra exerted by Pressure on the Retina, and their Application to the Diagnosis of the Affections of the Retina and its Appendages," by Dr. A. Waller. These observations relate to the luminous spectra which appear in the field of vision when the eyeball is compressed, or when the head has received a sharp blow, and in various other circumstances. After having described the discoveries of Sir Isaac Newton and others, the author goes on to relate his own observations, and finds that these spectra vary according to the part of the eyeball which is compressed. If compressed at the upper part they appear to be most bright, and consist of several concentric rings alternately bright and dark. He shows that these spectra may be employed with great advantage as a means of discriminating the diseases of the retina and optic nerve from those which affect the crystalline lens, the iris, and the other parts in front of the retina. In amaurosis, glaucoma, and other affections of the nervous parts, the spectra are found to become more faint in proportion as the nervous powers are injured, and are entirely absent when the visual powers are more deeply impaired. On the other hand, in those numerous affections of the eye where the rays of light can no longer form their images on the retina on account of the opacity of the parts which they have to traverse, the ocular spectra are found to be unimpaired in their brightness. The author cited numerous cases in confirmation of this statement.
— Athenæum, No. 1087.
Chemical science. On the Coloured Photographic Image of the Solar Spectrum.
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MDCCCXLIX (1849)By M. Edmond Becquerel.
The author, in the course of his researches upon the chemical action of Light, was led to this remarkable fact, that the Solar Spectrum could form its image with colours corresponding to its own, upon a plate of silver properly prepared. For this purpose, the plate may be attacked by free chlorine, with the precautions indicated in the note presented to the Academy: the sensitive coating which is formed upon the surface of the plate is red in the prismatic red, yellow in the yellow, green in the green, blue in the blue, and violet in the violet. The reddish tint turns to purple in the extreme red, and extends even beyond Fraunhofer's line A; as to the violet, it continues far beyond A, gradually becoming more feeble. When the action of the spectrum is permitted to last a long time, the tints become dark, and the image finally takes the metallic lustre: the colours have then disappeared.
According to the preparation of the plate and the thickness of the sensitive coating, any of the tints of the spectrum may be made to predominate: thus, a surface well prepared, and previously in diffused light coloured purple under a deep red glass, gives a beautiful coloured photographic image of the spectrum, in which the orange, yellow, the green, and the blue, are marked with the greatest clearness. The substance formed upon the surface of the silver is not the white chloride, but probably a subchloride, since it is not strongly coloured beyond the visible violet, as the chemically precipitated chloride is, and the maximum of action is found in the yellow, where the maximum of luminous intensity is, or moves towards the red, according to the preparation to the plate. To get a tolerably rapid action, it is necessary to use a strongly concentrated spectrum. These effects explain the red colour of the chloride of silver, and of the sensitive paper formed with that compound, in the red rays, which has been already observed by MM. Seebeck and Herschel.
The author has succeeded in preparing, by means of free chlorine, and also by using bichloride of copper, a sensitive coating of the chloride of silver, so impressed that now only certain parts of the spectrum are represented with their colours; but besides, white light makes a white impression.
The compound formed upon the surface of the silver by the action of chlorine, is the only one hitherto found which shows the properties here mentioned. Up to the present time, it appears necessary to keep the coloured prismatic images in the dark, and the author has not found the means of fixing it under the influence of light. If the fixation could be accomplished, and if the sensitiveness of the material was greater, we could not only draw, but also paint by light; nevertheless, the results mentioned show that the solution of the problem is possible.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)By M. Edmond Becquerel.
The author, in the course of his researches upon the chemical action of Light, was led to this remarkable fact, that the Solar Spectrum could form its image with colours corresponding to its own, upon a plate of silver properly prepared. For this purpose, the plate may be attacked by free chlorine, with the precautions indicated in the note presented to the Academy: the sensitive coating which is formed upon the surface of the plate is red in the prismatic red, yellow in the yellow, green in the green, blue in the blue, and violet in the violet. The reddish tint turns to purple in the extreme red, and extends even beyond Fraunhofer's line A; as to the violet, it continues far beyond A, gradually becoming more feeble. When the action of the spectrum is permitted to last a long time, the tints become dark, and the image finally takes the metallic lustre: the colours have then disappeared.
According to the preparation of the plate and the thickness of the sensitive coating, any of the tints of the spectrum may be made to predominate: thus, a surface well prepared, and previously in diffused light coloured purple under a deep red glass, gives a beautiful coloured photographic image of the spectrum, in which the orange, yellow, the green, and the blue, are marked with the greatest clearness. The substance formed upon the surface of the silver is not the white chloride, but probably a subchloride, since it is not strongly coloured beyond the visible violet, as the chemically precipitated chloride is, and the maximum of action is found in the yellow, where the maximum of luminous intensity is, or moves towards the red, according to the preparation to the plate. To get a tolerably rapid action, it is necessary to use a strongly concentrated spectrum. These effects explain the red colour of the chloride of silver, and of the sensitive paper formed with that compound, in the red rays, which has been already observed by MM. Seebeck and Herschel.
The author has succeeded in preparing, by means of free chlorine, and also by using bichloride of copper, a sensitive coating of the chloride of silver, so impressed that now only certain parts of the spectrum are represented with their colours; but besides, white light makes a white impression.
The compound formed upon the surface of the silver by the action of chlorine, is the only one hitherto found which shows the properties here mentioned. Up to the present time, it appears necessary to keep the coloured prismatic images in the dark, and the author has not found the means of fixing it under the influence of light. If the fixation could be accomplished, and if the sensitiveness of the material was greater, we could not only draw, but also paint by light; nevertheless, the results mentioned show that the solution of the problem is possible.
Chemical science. Whitening Lace.
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MDCCCXLIX (1849)M. Blanchet has described to the Paris Academy of Sciences, the serious consequences resulting from the process of Whitening Brussels Lace to the persons employed in it. In this process the carbonate of lead is used; and a large portion of it is carried into the atmoshphere, where it is inhaled, and thus produces a serious affection of the intestines. It is also very injurious to the sight and to the hearing. M. Leroy D'Etiolles submitted a new and improved lithotritic instrument.
- Athenæum, No. 1051.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
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London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)M. Blanchet has described to the Paris Academy of Sciences, the serious consequences resulting from the process of Whitening Brussels Lace to the persons employed in it. In this process the carbonate of lead is used; and a large portion of it is carried into the atmoshphere, where it is inhaled, and thus produces a serious affection of the intestines. It is also very injurious to the sight and to the hearing. M. Leroy D'Etiolles submitted a new and improved lithotritic instrument.
- Athenæum, No. 1051.
Chemical science. Colouring Matters of Madder.
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MDCCCXLIX (1849)Mr. J. Higgin, in a paper read to the British Association, after describing the three Colouring Matters of Madder-xanthin, rubiacin, and alizarin, and the means he employs to separate them in a pure form, - proceeds to show that the opinion usually entertained — that it is the alizarin only which is the valuable part of madder — is incorrect; and several experiments were adduced to prove that in proper circumstances, such as obtain in ordinary madder dyeing, the xanthin and rubiacin contribute very materially to the effect. They are shown not to act directly, but become changed into alizarin, which then combines with the mordants. This change is considered by the author to be induced by a peculiar azotized ferment found in madder, whereby xanthin becomes rubiacin, and this latter alizarin; and the opinion is held out that all colouring matter in madder is derived primarily from xanthin.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)Mr. J. Higgin, in a paper read to the British Association, after describing the three Colouring Matters of Madder-xanthin, rubiacin, and alizarin, and the means he employs to separate them in a pure form, - proceeds to show that the opinion usually entertained — that it is the alizarin only which is the valuable part of madder — is incorrect; and several experiments were adduced to prove that in proper circumstances, such as obtain in ordinary madder dyeing, the xanthin and rubiacin contribute very materially to the effect. They are shown not to act directly, but become changed into alizarin, which then combines with the mordants. This change is considered by the author to be induced by a peculiar azotized ferment found in madder, whereby xanthin becomes rubiacin, and this latter alizarin; and the opinion is held out that all colouring matter in madder is derived primarily from xanthin.
17.5.20
Natural philosophy. On the Existence of the Colour Brown.
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MDCCCXLIX (1849)By Ernest Brucke.
Brown is wanting in the prismatic spectrum, and its relation to the colours of the spectrum is as yet unknown. Any one may, however, easily convince himself that brown is nothing more than the complementary colour to that of Herschel's lavender-gray rays, i. e. white light from which these rays have been removed.
For this purpose, separate plates should be split from crystallized gypsum in such a manner that on one side they are as thin as possible, and from it gradually increase in thickness in broad terraces. One of these plates is placed under the microscope, which must be furnished with two Nichol's prisms, one beneath the object-glass, and one in the eye piece, and so arranged, the prisms being parallel, and the linear magnifying power being about twenty diameters (at a distance of eight French inches) that the above-mentioned thin side is in the field. If it is sufficiently ain, no colour is perceived immediately at the side; but as we proceed towards the thicker part, at first a pale brown tint becomes visible, as if we were looking through a very thin plate of horn, and as the thickness of the plate gradually increases in broad and low terraces, the brown continues to become darker until it assumes a deep and pure nut-brown colour, without the intervention of any of the prismatic colours which the thicker parts of the plate exhibit.
It is evident that the plate at the margin where it appears colourless is so thin, that the difference of the path of the ordinary and extraordinary ray on their exit does not amount to half the length of a wave for any colour. Thus interference of the most refractive rays does not occur until the thickness is greater, and the brown colour must therefore be produced by the disappearance of the lavender-gray rays from the compound light.
The correctness of this conclusion is readily tested. On crossing the prisms, it is seen that whilst in the case of all the other colours of the plate the well known complementary colours appear, that portion which was previously brown becomes coloured lavender-gray, and the intensity of this colour is in proportion to the depth of the brown previously observed at the same spot.
— From Poggendorff’s Annalen: read before the Physical Society of Berlin: Phil. Mag. No. 222.
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By John Timbs,
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MDCCCXLIX (1849)By Ernest Brucke.
Brown is wanting in the prismatic spectrum, and its relation to the colours of the spectrum is as yet unknown. Any one may, however, easily convince himself that brown is nothing more than the complementary colour to that of Herschel's lavender-gray rays, i. e. white light from which these rays have been removed.
For this purpose, separate plates should be split from crystallized gypsum in such a manner that on one side they are as thin as possible, and from it gradually increase in thickness in broad terraces. One of these plates is placed under the microscope, which must be furnished with two Nichol's prisms, one beneath the object-glass, and one in the eye piece, and so arranged, the prisms being parallel, and the linear magnifying power being about twenty diameters (at a distance of eight French inches) that the above-mentioned thin side is in the field. If it is sufficiently ain, no colour is perceived immediately at the side; but as we proceed towards the thicker part, at first a pale brown tint becomes visible, as if we were looking through a very thin plate of horn, and as the thickness of the plate gradually increases in broad and low terraces, the brown continues to become darker until it assumes a deep and pure nut-brown colour, without the intervention of any of the prismatic colours which the thicker parts of the plate exhibit.
It is evident that the plate at the margin where it appears colourless is so thin, that the difference of the path of the ordinary and extraordinary ray on their exit does not amount to half the length of a wave for any colour. Thus interference of the most refractive rays does not occur until the thickness is greater, and the brown colour must therefore be produced by the disappearance of the lavender-gray rays from the compound light.
The correctness of this conclusion is readily tested. On crossing the prisms, it is seen that whilst in the case of all the other colours of the plate the well known complementary colours appear, that portion which was previously brown becomes coloured lavender-gray, and the intensity of this colour is in proportion to the depth of the brown previously observed at the same spot.
— From Poggendorff’s Annalen: read before the Physical Society of Berlin: Phil. Mag. No. 222.
Natural philosophy. Ideal Colours.
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MDCCCXLIX (1849)Perhaps the most interesting part of M. Hundertpfund's work, just quoted, is the chapter on Ideal Colours (Idealn Farben); because it discloses the principles on which the system in question is built.
The author sets out with a definition of light and darkness as they relate to colour. But his definition is not in harmony with that commonly accepted. Light is generally supposed to be a substance, and darkness to be the mere absence of light. But M. Hundertpfund treats them both as substances each a sort of sympathetic affection for each other, and as having, each of them, a disposition to attract and expand. "When light," he says, "yields itself up to darkness, the darkness receives and draws it into its own body, and becomes softened by it. The light, however, suffers by the incorporation. On its first entrance into darkness it loses its primitive splendour, and exhibits itself as a blue transparent object. As it enters more deeply into darkness its blue bcomes more and more tinged with red, until a point is reached where darkness has completely absorbed the light, and then a perfect red appears, softening the austerity of the gloom, and exhibiting itself in great splendour."
This, according to the author's hypothesis, is the natural cause of the blue and red and their derivative purple. The cause of the yellow he attributes to a disposition on the part of the light to release itself from the darkness after being absorbed by it. On reappearing, influenced by darkness, it assumes a yellow colour, tinged at first with red, and then less and less so till the yellow stands alone. The intermediate colour is of course orange: — i. e. the derivative of red and yellow.
The other derivative, green, is supposed to be formed in consequence of a disposition on the part of the yellow, or rather of the light, to direct itself towards the point where it first entered the darkness, and so to come into contact with the blue: which seems to presume that there is in light a propensity to take a circular course through darkness, and to return to the point at which it set out.
We know but little about light; the nature of which, like that of many other things, has as yet been more the subject of conjecture than of demonstration. M. Hundertpfund's ideas must therefore stand or fall according to their intrinsic justice but there are many things which seem to confirm them. For instance, let any one light a candle in a dark room, and watch the progress of its ignition. He will observe (particularly if the candle lights slowly) that its first flame is blue, that it then becomes red, and at length blazes up from an orange into a bright yellow. This course of transition is in harmony with M. Hundertpfund's hypothesis; for it will be the natural result of the following causes: — light is produced, and as it enters into the darkness (which is at first stronger than the light) it becomes blue; then, as it is further affected, violet and red: and when at last it frees itself from the darkness and triumphs over it, orange and yellow. It may be remarked, also, that in daylight, in the open air or in a room lighted up strongly by sunshine, this transition of colours is not perceived, and that in proportion as the room is in shade will the transition be more and more strongly visible.
— Letter, in the Athenæum, No. 1084.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)Perhaps the most interesting part of M. Hundertpfund's work, just quoted, is the chapter on Ideal Colours (Idealn Farben); because it discloses the principles on which the system in question is built.
The author sets out with a definition of light and darkness as they relate to colour. But his definition is not in harmony with that commonly accepted. Light is generally supposed to be a substance, and darkness to be the mere absence of light. But M. Hundertpfund treats them both as substances each a sort of sympathetic affection for each other, and as having, each of them, a disposition to attract and expand. "When light," he says, "yields itself up to darkness, the darkness receives and draws it into its own body, and becomes softened by it. The light, however, suffers by the incorporation. On its first entrance into darkness it loses its primitive splendour, and exhibits itself as a blue transparent object. As it enters more deeply into darkness its blue bcomes more and more tinged with red, until a point is reached where darkness has completely absorbed the light, and then a perfect red appears, softening the austerity of the gloom, and exhibiting itself in great splendour."
This, according to the author's hypothesis, is the natural cause of the blue and red and their derivative purple. The cause of the yellow he attributes to a disposition on the part of the light to release itself from the darkness after being absorbed by it. On reappearing, influenced by darkness, it assumes a yellow colour, tinged at first with red, and then less and less so till the yellow stands alone. The intermediate colour is of course orange: — i. e. the derivative of red and yellow.
The other derivative, green, is supposed to be formed in consequence of a disposition on the part of the yellow, or rather of the light, to direct itself towards the point where it first entered the darkness, and so to come into contact with the blue: which seems to presume that there is in light a propensity to take a circular course through darkness, and to return to the point at which it set out.
We know but little about light; the nature of which, like that of many other things, has as yet been more the subject of conjecture than of demonstration. M. Hundertpfund's ideas must therefore stand or fall according to their intrinsic justice but there are many things which seem to confirm them. For instance, let any one light a candle in a dark room, and watch the progress of its ignition. He will observe (particularly if the candle lights slowly) that its first flame is blue, that it then becomes red, and at length blazes up from an orange into a bright yellow. This course of transition is in harmony with M. Hundertpfund's hypothesis; for it will be the natural result of the following causes: — light is produced, and as it enters into the darkness (which is at first stronger than the light) it becomes blue; then, as it is further affected, violet and red: and when at last it frees itself from the darkness and triumphs over it, orange and yellow. It may be remarked, also, that in daylight, in the open air or in a room lighted up strongly by sunshine, this transition of colours is not perceived, and that in proportion as the room is in shade will the transition be more and more strongly visible.
— Letter, in the Athenæum, No. 1084.
Natural philosophy. New System of Oil-Painting.
The Year-Book of Facts in Science and Art
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in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
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David Bogue, Fleet Street,
MDCCCXLIX (1849)M. Libertat Hundertpfund, the historical painter at Augsberg, has published a work, entitled "The Art of Painting brought back to its Simplest and Surest Principles," (Die Malerie, &c.), in which a very valuable discovery has been applied to the practice of oil-painting, so as to render it comparatively easy, and to ground it on an intelligible theory. While he was busied with experiments to find out a better mode of imitating the transparency of the natural shadow, a glass prism fell into his hands. This was a source of great delight to him. The colours produced by it, and their operation on each other, became an engrossing subject of his thoughts; and on one occasion his fancy led him to imagine the three primitive colours, — red, blue, and yellow — springing like rays from the centre of a circle to three equidistant points in its circumference, and affecting the intermediate spaces there by producing their three derivative colours, — purple, orange, and green. This was a mere play of imagination; for at the moment of its occurrence he had not any idea of the discovery up to which he was subsequently led.
*A circular arrangement of colours somewhat similar to that which oc curred to M. Hundertpfund is proposed by Goethe in his "Farbenlehre," but without deducing from it the consequences on which the present theory is founded.Shortly after this arrangement had occurred to M. Hundertpfund, his attention was accidentally drawn to an unfinished picture by Titian; and the state of it enabled him to remark that the shades of a red object there had been produced by under-painting them with green, — that is to say, Titian had first painted all the shadows with a green colour, and had afterwards painted them over with red. This mode of under-painting was not quite new to M. Hundertpfund; for he had observed that landscape painters often produced the shadows of a green object by preparing them with burnt sienna, — and this tint appeared to his eye to partake more of red than of any other colour. These two facts, as they travelled about in his mind, came there into company with his previously imagined circle of colours, and caused him to remark that if the radius (which indicates the ray of red colour), were produced in a straight line to the opposite extremity of the circle, it would reach just that point at which the green would be predominant: and this observation induced him to establish in his own thoughts a particular axiom, namely, that green is the opposite — the antipodes of red. Following up this train of speculation, he began to believe that the success which attended Titian's practice of preparing red shadows with green colour might be referable to a natural cause; and that such a cause might be equally operative with regard to colour, so as to justify the establishment of a general rule, that all shadows ought to be prepared with the opposite to which they relate. Proof was already before him that the shadow on red could be most effectively prepared with its opposite green; and it remained to be proved whether the shadows on green could not be prepared with its opposite red — and also, whether the shadows on the other primitive colours could not be prepared with their respective opposites. M. Hundertpfund found this theory justified not only with regard to the primitive colours and their derivatives, but also with regard to those tints which occupy the intermediate spaces in the circle between the primitive and derivative colours*.
The different tints produced according to this system of oil painting are divided by M. Hundertpfund into colours, whole-tones, and half-tones:
*"The Art of Painting Restored to its simplest and surest Principles." Published by D. Bogue, Fleet Street.The reader will find this new system more fully detailed in the Athenæum, No. 1084: and a translation of M. Hundertpfund’s work has appeared in London.*
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)M. Libertat Hundertpfund, the historical painter at Augsberg, has published a work, entitled "The Art of Painting brought back to its Simplest and Surest Principles," (Die Malerie, &c.), in which a very valuable discovery has been applied to the practice of oil-painting, so as to render it comparatively easy, and to ground it on an intelligible theory. While he was busied with experiments to find out a better mode of imitating the transparency of the natural shadow, a glass prism fell into his hands. This was a source of great delight to him. The colours produced by it, and their operation on each other, became an engrossing subject of his thoughts; and on one occasion his fancy led him to imagine the three primitive colours, — red, blue, and yellow — springing like rays from the centre of a circle to three equidistant points in its circumference, and affecting the intermediate spaces there by producing their three derivative colours, — purple, orange, and green. This was a mere play of imagination; for at the moment of its occurrence he had not any idea of the discovery up to which he was subsequently led.
*A circular arrangement of colours somewhat similar to that which oc curred to M. Hundertpfund is proposed by Goethe in his "Farbenlehre," but without deducing from it the consequences on which the present theory is founded.Shortly after this arrangement had occurred to M. Hundertpfund, his attention was accidentally drawn to an unfinished picture by Titian; and the state of it enabled him to remark that the shades of a red object there had been produced by under-painting them with green, — that is to say, Titian had first painted all the shadows with a green colour, and had afterwards painted them over with red. This mode of under-painting was not quite new to M. Hundertpfund; for he had observed that landscape painters often produced the shadows of a green object by preparing them with burnt sienna, — and this tint appeared to his eye to partake more of red than of any other colour. These two facts, as they travelled about in his mind, came there into company with his previously imagined circle of colours, and caused him to remark that if the radius (which indicates the ray of red colour), were produced in a straight line to the opposite extremity of the circle, it would reach just that point at which the green would be predominant: and this observation induced him to establish in his own thoughts a particular axiom, namely, that green is the opposite — the antipodes of red. Following up this train of speculation, he began to believe that the success which attended Titian's practice of preparing red shadows with green colour might be referable to a natural cause; and that such a cause might be equally operative with regard to colour, so as to justify the establishment of a general rule, that all shadows ought to be prepared with the opposite to which they relate. Proof was already before him that the shadow on red could be most effectively prepared with its opposite green; and it remained to be proved whether the shadows on green could not be prepared with its opposite red — and also, whether the shadows on the other primitive colours could not be prepared with their respective opposites. M. Hundertpfund found this theory justified not only with regard to the primitive colours and their derivatives, but also with regard to those tints which occupy the intermediate spaces in the circle between the primitive and derivative colours*.
The different tints produced according to this system of oil painting are divided by M. Hundertpfund into colours, whole-tones, and half-tones:
The colours are, Primitive or Generic (Stammfarben), i.e. red, blue, and yellow, and — Derivative or Secondary (Nebenfarben), i.e. violet, orange, and green.
The whole-tones are produced by a mixture of any two primitive colours in unequal proportions, e.g. red and yellow, so as to form a red-orange or an orange-red-or by a mixture of derivatives when any of the primitive colours become thereby predominant.
The half-tones are produced by an equally proportioned mixture of two derivative colours, e. g. green and orange.
*"The Art of Painting Restored to its simplest and surest Principles." Published by D. Bogue, Fleet Street.The reader will find this new system more fully detailed in the Athenæum, No. 1084: and a translation of M. Hundertpfund’s work has appeared in London.*
Mechanical an Useful arts. Merble Veneering, or Slaty Paint.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)In Ohio, according to a New York paper, a Mr. Blake, of Akron, has discovered a curious mineral, soft at first, and like indigo, but hardening in a few days into a slaty stone. On analysis, it is found to consist of about one-half silica, one-fourth alumina, with magnesia, oxide and sulphate of iron, lime, and carbon. By reducing it to fine powder, mixing with linseed oil into thick paint, and applying it with a brush to wood, iron, tin, zinc, or brick, it becomes, after a few months’ exposure, perfectly hard and indestructible. As a protection against fire, it is said to be invaluable. In the west it is in large demand for covering roofs of buildings, for bridges and fences, &c., all of which it protects from weather as well as from fire. School slates are manufactured by applying it to thin wood or pasteboard. On wooden mantel fronts and tables its appearance, when polished, is held to be not inferior to the finest Egyptian marble. Mr. Blake has procured a patent for his discovery. Would not Portland cement, in fine powder, and thus applied, with linseed oil, produce a slaty veneer over similar surfaces? We make a present of the suggestion to the Portland cement manufacturers. Parian cement mixes with oil, and might thus, we think, be used as paint, or for stony veneering; and certainly the surface of blocks of Portland cement reminds one a good deal of slate: the hardening, too, from a soft or moist state very much adds to the resemblance which it bears to this new world’s wonder. Silica, with lime, has been found, if we mistake not, to form a sort of glaze well adapted to give a stony veneering, like this, to plaster.
— Builder, No. 298.
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)In Ohio, according to a New York paper, a Mr. Blake, of Akron, has discovered a curious mineral, soft at first, and like indigo, but hardening in a few days into a slaty stone. On analysis, it is found to consist of about one-half silica, one-fourth alumina, with magnesia, oxide and sulphate of iron, lime, and carbon. By reducing it to fine powder, mixing with linseed oil into thick paint, and applying it with a brush to wood, iron, tin, zinc, or brick, it becomes, after a few months’ exposure, perfectly hard and indestructible. As a protection against fire, it is said to be invaluable. In the west it is in large demand for covering roofs of buildings, for bridges and fences, &c., all of which it protects from weather as well as from fire. School slates are manufactured by applying it to thin wood or pasteboard. On wooden mantel fronts and tables its appearance, when polished, is held to be not inferior to the finest Egyptian marble. Mr. Blake has procured a patent for his discovery. Would not Portland cement, in fine powder, and thus applied, with linseed oil, produce a slaty veneer over similar surfaces? We make a present of the suggestion to the Portland cement manufacturers. Parian cement mixes with oil, and might thus, we think, be used as paint, or for stony veneering; and certainly the surface of blocks of Portland cement reminds one a good deal of slate: the hardening, too, from a soft or moist state very much adds to the resemblance which it bears to this new world’s wonder. Silica, with lime, has been found, if we mistake not, to form a sort of glaze well adapted to give a stony veneering, like this, to plaster.
— Builder, No. 298.
13.5.20
Mechanical an Useful arts. Anastatic Printing.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)Mr. H. E. Strickland, M.A., of Oxford, in conjunction with Mr. Delamotte, who has established an Anastatic Press in the above city, has succeeded in transferring and printing from drawings made on paper with lithographic chalk. He made a hasty sketch on common drawing paper (of good quality, but not very smooth surface), and sent it to Mr. Delamotte's press. Within an hour, Mr. Strickland received a perfect fac-simile of the original drawing, not to be distinguished from a lithograph. Further experiments will be required to prove whether this method can supersede the finer branches of lithographic drawing; or, in other words, whether paper can be made with a surface as finely and uniformly grained as that which is produced on the stone. But for less delicate and elaborate works there can be no doubt that the antistatic process has two advantages over lithography: first, we dispense with the cost and inconvenience of transporting and using heavy stones. The traveller may now fill his portfolio with sketches made in the field, with lithographic chalk on paper, and may afterwards print of as many copies of these sketches as he pleases. And secondly, the drawings do not require to be reversed, or even copied, — a great saving of the artist's time and labour.
— Athenæum, No. 1059.
A correspondent of the Athenæum, No. 1060, suggests that if India paper, or, as it is sometimes called, Chinese paper, of the best quality, be mounted on soft plate-paper (by pressing the two together, while damp, through a lithographic press, the India paper being in contact with the blank surface of a lithographic stone, which has been properly grained as for a fine lithographic chalk drawing, precisely as India paper impressions of lithographs are taken), and afterwards dried under a slight pressure, to preserve the flatness of the double sheet, it will be found that the surface of the India paper has had a clear sharp grain communicated to it by the grain of the stone, of which it will be the exact counterpart — but little, if at all, inferior to it — adapted to receive drawings done with lithographic chalk, that may vie in finish, force, and delicacy, with highly-finished drawings done on the stone. These drawings so executed may, as Mr. Strickland proposes, be subjected to the anastatic process; and, adds the writer, "I have little doubt that very beautiful and highly-finished works may most conveniently be produced in this manner. I may observe that I have frequently had paper prepared in this way, as I consider it a most agreeable preparation for pencil and chalk drawings of the ordinary description; and I have found that it would be comparatively inexpensive, as it may be done by any lithographic printer."
Mr. Strickland has since tried various kinds of paper as a medium for the lithographic chalk, and finds that the so-called metallic paper (prepared for metallic pencils) makes the nearest approach to the effect of lithography. Fine drawing paper, smooth but not glossy, is the next best material. Mr. Delamotte has found India paper too tender a substance for transferring to zinc. For fine subjects it is essential that the lithographic chalk be of a hard quality and cut to a fine point. The papyrographs thus produced appear to the eye like lithographs; but, when examined by a lens, they exhibit a different effect, in consequence of the surface of paper consisting of horizontal fibres, while that of a lithographic stone is made up of small conical points. That the latter structure might be given to paper by mixing some finely-powdered mineral matter with the fibrous pulp. Calcareous substances, however, will effervesce with the acids used in transferring, and siliceous ones would be too rough and gritty. Some hard aluminous matter, such as powdered slate, or brick-dust, if mixed in due proportion with the paper, would probably enable us to produce the effect of lithography without the use of stones.
12.5.20
Mechanical an Useful arts. Lithography.
The Year-Book of Facts in Science and Art
Exhibiting the Most Important discoveries and Improvements of the past year,
in mechanics and the useful arts; natural philosophy; electricity; chemistry; zoology and biology; geology and geography; meteorology and astronomy.
By John Timbs,
editor of "the Arcana of Science and Art."
London:
David Bogue, Fleet Street,
MDCCCXLIX (1849)Mr. S. Williams has read to the Society of Arts, a paper, "On the History and Progress of Lithography." He commenced by stating that Lithography, like many other important discoveries, owed its birth to mere chance; and proceeded to give a brief account of the circumstances under which Alois Senefelder turned his attention to the discovery of a ready means of printing what as a writer and aspirant to histrionic fame he produced. "I had just succeeded," states S-nefelder, "in polishing a stone plate which I intended to cover with etching ground in order to continue my exertions in writing backwards, when my mother entering the room, required me to write a washing-bill. It so happened that there was not a morsel of writing paper or ink at hand, — nor had we any one to send for these materials; I therefore resolved to write with my ink, prepared with wax, soap, and lamp black, upon the stone which I had just polished, as the matter would admit of no delay. Some time after, requiring the stone for use, and the writing being as I had left it, it occurred to me whether I could not bite in the stone with acid." This Senefelder succeeded in doing; — and thus the art was discovered. Baron Aretin in Munich, Count Lasteyrie in Paris, and Mr. Ackermann in London, fostered the rising art; and in 1819 Senefelder's account of lithography appeared, with illustrations showing the then state of the art. Mr. Hullmandel (observes Mr. Williams) has done more to improve and establish lithography in England, and to make it available to artists, than any other individual, Senefelder alone excepted. The author proceeded to describe the nature of the lithographic stone, and the difficulties which had to be overcome by the first artists, not merely in drawing upon the stone, but also in enabling the printer to reproduce their works. The specimens exhibited he divided into six classes; and stated that each of the specimens in the various classes is produced in the following manner: — Class 1. Drawings, on one stone only, with the crayon, and printed in black ink. Class 2. Drawings with the crayon on two or three stones, and printed with neutral tints. Class 3. Drawing made on several stones, and printed in colours. Class 4. Drawings in lithotint with the brush and liquid a process patented by Mr. Hullmandel. Class 5. Drawings made with a stump, used as in making chalk drawings. This process is also patented. Class 6 consists of specimens of printing from transfers from old prints, newspapers, and pen drawings, by a process known and patented as the anastatic process.
— Athenæum, No. 1054.
1.5.20
Tapettien valinnasta.
Aamulehti 282, 6.12.1923
Värityksen kannalta katsoen on seinäverho tärkein tekijä huoneessa, sillä seinien suuret pinta-alat ovat ikäänkuin sisustan tekemän vaikutuksen perustana, ue ovat taustana, jota vastaan huonekalut ja muut sisustusesineet kuvastuvat. Kuitenkin ei yksistään väri vaikuta huoneen tekemään kokonaisvaikutukseen, vaan on myöskin seinäverhossa esiintyvällä satunnaisella ornamentiikillä ja viivain elelyllä suuri tehoisuus siihen. Seinäverhoja valittaessa on sangen monta eri seikkaa huomioon otettava, ja siinäpä onkin vaikeus, jota tavallisessa puheessa kutsumme "tapettien valinnaksi".
Kotia sisustettaessa esiintyvä persoonallinen kaunoaisti ja henkilökohtaiset toivomukset ovat siihen määrään monipuoliset, ettei voida asettaa minkäänlaista pysyvää mittamäärää; Kuitenkin haluan antaa muutamia viittauksia, jotka ehkä ovat hyödyksi tapetteja valittaessa. Huoneessa, jossa erittäin halutaan saada näkyviin huonekalujen kauniit piirteet ja jossa halutaan varustaa taideteoksille edullinen ja tyyni tausta, on puollettava seinäverhoa, joka vaikuttaa yksiväriseltä ja jossa ornamentiikki ei vahvasti esiinny, mutta kun seinien tekemän vaikutuksen avulla halutaan saada aikaan vilkkaampi ja iloisempi sävy ja samalla halutaan vähemmän korostaa huonekaluja ja huoneessa olevia taideteoksia, on runsaammalla ornamentiikillä ja vahvemmilla väreillä varustetta tapetti erinomaisen tehokas.
Useampia vuosia perättäin on taideteollisuuden alalla melkoisen voimakas pyrkimys tummiin väreihin, harmaaseen ja ruskeaan, ollut voitolla. On pyritty luomaan huoneen sisusta selväpiirteisen tyyneeksi, jotta tämän kautta ne taide-esineet, joita erityisesti on haluttu korostaa, esiintyisivät voimakkaammin ja edullisemmin. Minusta näyttää kuitenkin siltä, kuin tässä olisi tähdätty harhaan.
Valosta niukassa maassamme on riittämään asti hämärää, järjestämättä lisäksi vielä huoneidemme sisustankin harmaan, ruskean tai tumman väriseksi. Menneisiin aikoihin katsahtaessa huomaamme, että vähimmin taiteelliselle ajanjaksolle myöhempänä aikana, joka sattuu 1880-luvulla, juuri nämä värit ovat suuremmassa määrässä luonteenomaiset kuin muille ajanjaksoille, kuin sitävastoin melkeen kaikkina muina aikoina, erittäinkin varsinaisten tyyli-käännekohtien aikana värille sinänsä ja heleämmille, kirkkaammille värisoinnuille on osotettu melkoista huomiota.
Kaikki merkit - sekä nopeaan tykkivä elämä kuin myös yleinen makusuunta - viittaavat siihen, että kuljemme aikaa kohti tai elämme jo siinä, jolloin iloisemmat värisoinnut, runsaammat värivivahdukset pääsevät täydelleen esiintymään ja pysyvät tälle ajalle luonteenomaisina.
- Nils W.
Värityksen kannalta katsoen on seinäverho tärkein tekijä huoneessa, sillä seinien suuret pinta-alat ovat ikäänkuin sisustan tekemän vaikutuksen perustana, ue ovat taustana, jota vastaan huonekalut ja muut sisustusesineet kuvastuvat. Kuitenkin ei yksistään väri vaikuta huoneen tekemään kokonaisvaikutukseen, vaan on myöskin seinäverhossa esiintyvällä satunnaisella ornamentiikillä ja viivain elelyllä suuri tehoisuus siihen. Seinäverhoja valittaessa on sangen monta eri seikkaa huomioon otettava, ja siinäpä onkin vaikeus, jota tavallisessa puheessa kutsumme "tapettien valinnaksi".
Kotia sisustettaessa esiintyvä persoonallinen kaunoaisti ja henkilökohtaiset toivomukset ovat siihen määrään monipuoliset, ettei voida asettaa minkäänlaista pysyvää mittamäärää; Kuitenkin haluan antaa muutamia viittauksia, jotka ehkä ovat hyödyksi tapetteja valittaessa. Huoneessa, jossa erittäin halutaan saada näkyviin huonekalujen kauniit piirteet ja jossa halutaan varustaa taideteoksille edullinen ja tyyni tausta, on puollettava seinäverhoa, joka vaikuttaa yksiväriseltä ja jossa ornamentiikki ei vahvasti esiinny, mutta kun seinien tekemän vaikutuksen avulla halutaan saada aikaan vilkkaampi ja iloisempi sävy ja samalla halutaan vähemmän korostaa huonekaluja ja huoneessa olevia taideteoksia, on runsaammalla ornamentiikillä ja vahvemmilla väreillä varustetta tapetti erinomaisen tehokas.
Useampia vuosia perättäin on taideteollisuuden alalla melkoisen voimakas pyrkimys tummiin väreihin, harmaaseen ja ruskeaan, ollut voitolla. On pyritty luomaan huoneen sisusta selväpiirteisen tyyneeksi, jotta tämän kautta ne taide-esineet, joita erityisesti on haluttu korostaa, esiintyisivät voimakkaammin ja edullisemmin. Minusta näyttää kuitenkin siltä, kuin tässä olisi tähdätty harhaan.
Valosta niukassa maassamme on riittämään asti hämärää, järjestämättä lisäksi vielä huoneidemme sisustankin harmaan, ruskean tai tumman väriseksi. Menneisiin aikoihin katsahtaessa huomaamme, että vähimmin taiteelliselle ajanjaksolle myöhempänä aikana, joka sattuu 1880-luvulla, juuri nämä värit ovat suuremmassa määrässä luonteenomaiset kuin muille ajanjaksoille, kuin sitävastoin melkeen kaikkina muina aikoina, erittäinkin varsinaisten tyyli-käännekohtien aikana värille sinänsä ja heleämmille, kirkkaammille värisoinnuille on osotettu melkoista huomiota.
Kaikki merkit - sekä nopeaan tykkivä elämä kuin myös yleinen makusuunta - viittaavat siihen, että kuljemme aikaa kohti tai elämme jo siinä, jolloin iloisemmat värisoinnut, runsaammat värivivahdukset pääsevät täydelleen esiintymään ja pysyvät tälle ajalle luonteenomaisina.
- Nils W.