Red DuraCHAPTER XVIII. Colouring Matters of Unknown Constitution.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

The "Red Dura" or "Durra" of the Soudan, also known as "Shikytan," consists of the deep reddish-brown sheaths of a grass, apparently the Andropogon sorghum (Brot), var. vulgaris, also known as the Sorghum vulgare (Pers.) or "Great millet," the grain of which provides so important a foodstuff. According to E. P. Brown, Inspector of the Blue Nile Province, the "Shikytan" is used for producing a red dye, practically utilised for staining a grass called "lanzura," employed in the manufacture of coloured "bursh" mats, but occasionally for the leather of "markubs" (Sudanese shoes). It is specially grown for dyeing purposes. A full account of the S. vulgare is given by Watt ("Dictionary of Economic Products of India," 6, [iii.], 289). The grain occasionally possesses a brick-red colour, and that at Harihar is used for preparing a red morocco from goat skin. The canes of S. saccharatum also, when pressed and allowed to ferment, develop a red or reddish-brown colour, and the dye thus produced can be extracted by means of dilute alkali. The Indian, Persian, Abyssinian, and Egyptian forms would seem to be derived from the A. sorghum, var. durrha; but the fact that this plant is so extensively cultivated in Egypt as a foodstuff and the "Shikytan" is grown entirely for dyeing purposes, seems to indicate that this latter is again a special variety.

The colouring matter, durasantalin, to which the formula C₁₆H₁₂O₅ has been provisionally assigned (Perkin, Chem. Soc. Trans., 1910, 97, 220), consists of a bright red or scarlet powder, possessing an ill-defined crystalline structure. It is soluble in alkalis with a redviolet colour, passing rapidly to brown on air oxidation, gives with alcoholic ferric chloride a brown liquid, and when fused with alkali, p-hydroxybenzoic acid and phloroglucinol, together with a trace of a third substance, probably p-hydroxyacetophenone, are produced. Durasantalin does not dye mordanted calico, but behaves as a substantive dyestuff towards wool upon which it produces a dull-red shade. A very permanent and slightly fuller colour can be produced by previously mordanting the wool with chromium. In some respects this dye resembles the santalin of sanderswood, but there can be no doubt that these substances are chemically distinct.

CamwoodCHAPTER XVIII. Colouring Matters of Unknown Constitution. The Insoluble Red Woods

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Camwood or "cambe wood," stated to be derived from a variety of Baphia nitida (cf. barwood), is very similar in general properties to the "insoluble red" dyewoods already described. It is, however, more expensive, yields deeper shades on dyeing, and its colouring matter is said to be more soluble than that present in the other woods.

It has been recently examined by O'Neill and Perkin (Chem. Soc. Trans.,1918, 113, 126), who employed for this purpose similar methods to those found serviceable with sanderswood (loc. cit.).

Iso-santalin, the main colouring matter, forms a chocolatecoloured powder, which on grinding becomes redder in appearance, and is readily soluble in boiling methylated spirit. When heated, it shows no sign of melting, darkens at 280°, and is fully decomposed at 290-300°, being then a carbonaceous powder. It possesses the formula C₂₂H₁₆O₆(OCH₃)₂, gives with alcoholic potassium acetate the salt C₉₆H₈₃O₂₂K or C₇₂H₆₅O₂₄K, shows evidence of the formation of soluble oxonium salts, and in general properties closely resembles its isomer santalin. The colour reactions and also the dyeing properties of the two compounds indicate, however, that they are distinct substances:

Alcoholic hydrobromic acid
Santalin - Crimson
Iso-santalin - Reddish-violet

Dilute sodium hydroxide
Santalin - Dull red
Iso-santalin - Dull violet

Alcoholic ferric chloride
Santalin - Violet
Iso-santalin - Bluish-violet

For dyeing the colouring matter in alcoholic solution was added to the water in the dye-bath and the dyeings were carried out (a) employing wool alone, (b) employing wool alone and subsequently saddening with bichrome, (c) employing wool mordanted with bichrome and cream of tartar, and (d) employing wool mordanted with bichrome and sulphuric acid.

Santalin
(a) Pale dull red.
(b) Dull reddish-brown
(c) Pale reddish-pink
(d) Pale red-pink

Iso-santalin
(a) Pale violet-red
(b) Dull violet-maroon
(c) Violet-red
(d) Violet-red weaker than (c)

Acetyl-iso-santalin, C₂₄H₁₈O₈(C₂H₃O)₄, consists of a deep salmoncoloured powder, and does not possess a definite melting-point, being gradually decomposed without fusion between 250-280°. A molecular weight determination employing naphthalene gave the high figure 2344, a result very similar to that given in these circumstances by acetyl-santalin itself, and which may possibly be due to the production of a colloidal solution.

Deoxy-iso-santalin, C₂₄H₁₈O₅(OCH₃)₂, corresponding to the deoxysantalin of sanderswood, is a scarlet amorphous powder which has not yet been obtained in a definitely crystalline condition. When heated, it did not show a distinct melting-point but decomposed at 160-165° with evolution of gas. A solution of this substance in absolute alcohol gives no immediate precipitate with potassium acetate, as happens in the case of iso-santalin, and only when excess of the reagent is employed is a gelatinous deposit formed.

A comparison of the colour reactions and dyeing properties of deoxy-iso-santalin (a) and deoxy-santalin (d) is given in the following table:

Alcoholic solution
(a) Orange
(b) Orange-brown

Alcoholic hydrobromic acid
(a) Bright crimson
(b) Scarlet

Dilute sodium hydroxide
(a) Crimson-scarlet
(b) Scarlet

Alcoholic ferric chloride
(a) Violet
(b) Maroon

The dyeing experiments were carried out by the same methods as those described above.

Deoxy-iso-santalin
(a) Pale red-violet
(b) Red puce
(c) Dull red-violet
(d) Pale dull red-violet

Deoxy-santalin
(a) Red
(b) Dull bluish-red
(c) Dull crimson
(d) Red

Acetyl-deoxy-iso-santalin, C₂₄H₂₀O₇(C₂H₃O)₄, when heated, fused and decomposed at 170 175. It consists of an almost colourless powder differing considerably in appearance from acetyl-iso-santalin. A molecular weight determination, employing naphthalene as solvent, gave the figure 1324, which is approximately half that found in the same circumstances for acetyl-iso-santalin.

By exhaustion with alcohol the sample of camwood employed by these authors gave 16 per cent, of extract.

Camwood does not appear to contain either ptero-carpin or homoptero-carpin.

NarrawoodCHAPTER XVIII. Colouring Matters of Unknown Constitution. The Insoluble Red Woods

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Narrawood, Pterocarpus spp., a well-known Philippine wood, according to Brooks (Philippine Journal of Science, 1910, v., 448), contains constituents very similar to those of sanderswood. To isolate the red colouring matter, the wood shavings were extracted with alcohol, the alcoholic extract concentrated and three volumes of water added. The solution was boiled to remove alcohol, and the red amorphous mass, which had then separated, was digested with about five parts of chloroform.

Thus obtained, Narrin consisted of a dark red amorphous powder, readily soluble in alcohol and insoluble in chloroform, which could not be obtained in a crystalline state. According to Brooks it is not identical with the santalin of sanderswood, for a preparation of this melted at 104°, whereas narrin does not melt but swells with charring about 180°. When fused with alkali narrin gives phloroglucinol and resorcinol, and by a slow oxidation with permanganate 12 grams gave 0,5 gram of a substance possessing a strong odour of vanillin. That it consisted of this substance was confirmed by its conversion into the phenylhydrazone which melted at 104. By distillation with zinc-dust narrin yields a small amount of resorcinol dimethyl ether. Narrin, like santalin, gives with alcoholic potassium acetate a precipitate of potassium salt, and the copper salt prepared in this way with copper acetate had the composition (C₁₅H₁₃C₅)₂Cu.

The dyeing properties of narrin are similar to those of santalin, but the shades produced are not very fast to soap.

In addition to colouring matter, Brooks isolated from narrawood both ptero-carpin and homoptero-carpin. By a careful examination of these substances he concluded that the formulæ previously assigned to them is incorrect, and should in reality be, respectively, C₁₄H₁₂O₄ and C₁₇H₁₅JO₄ (see "Sanderswood ").

CaliaturwoodCHAPTER XVIII. Colouring Matters of Unknown Constitution. The Insoluble Red Woods

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

This wood, the botanical origin of which appears to be unknown, is very similar to though somewhat darker in colour than sanderswood. It was imported from the East Indies and is stated to have been chiefly employed on the Continent. According to Franchimont and Sicherer (loc. cit.) it contains santalin but in larger amount than sanderswood.

BarwoodCHAPTER XVIII. Colouring Matters of Unknown Constitution. The Insoluble Red Woods(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Barwood is the wood of a large, fine tree, Baphia nitida (Lodd.), and is imported from the west coast of Africa, e.g. Sierra Leone, Angola, etc. In the log its physical properties are generally similar to those of sanderswood; in the rasped condition it has a somewhat brighter red colour and is devoid of aromatic odour. According to Girardin and Preisser, boiling water extracts about 7 per cent, of colouring matter, alcohol about 23 per cent., and hydrated ether about 19 per cent.

[---]

When the crude colouring matter of barwood, dissolved in alcohol, is poured into ether the main bulk of the santalin is precipitated. The ethereal liquid now contains, in addition to a colouring matter resembling deoxysantalin, two crystalline substances identical with those previously stated by Weidel (loc. cit.) as present in sanderswood. To isolate santal the ether solution is treated with hydrobromic acid to remove colouring matter, the colourless crystalline residue remaining after evaporation is washed with benzene, and recrystallised first from dilute and subsequently from absolute alcohol.

[---]

Sanderswood.CHAPTER XVIII. Colouring Matters of Unknown Constitution. The Insoluble Red Woods(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

This dyestuff, known also as Red Sanderswood, Santalwood, or Sandelwood, is the product of the Pterocarpus santalinus (Linn.), a papilionaceous tree growing in tropical Asia. It is, or was, imported from the East Indies, Ceylon, the coasts of Coromandel and Malabar, Golconda, Madagascar, etc. It comes into commerce in the form of hard heavy billets of a dull red colour. In the state of powder it gives off a faint aromatic odour like that of orris root, specially noticeable when it is heated or boiled with water. It yields to alcohol about 19,6 per cent, of extract, mainly consisting of colouring matter which is sparingly soluble even in boiling water, though readily in alcohol.

The resinous colouring matter was first isolated from Sanderswood by Pelletier (Ann. chim. phys., 1832, (2), 51, 193), who termed it sandel red, and assigned to it the formula Q H10O5. Meier (Arch. Pharm., 1848, 55, 285; 56, 41) named the colouring matter he obtained santalic acid or santalin, and though he did not analyse it, considered it to be a purer form of Pelletier's "sandel red". Meier extracted the wood with ether, evaporated the solution, and washed the residue with water. The impure product was dissolved in alcohol, the colouring matter precipitated by means of lead acetate, and the lead salt was collected and well washed with alcohol. In alcoholic suspension this lead compound was now decomposed by dilute sulphuric acid, and the clear liquid, after removal of the lead sulphate, was evaporated to crystallisation. Thus obtained, the santalin consisted of minute red crystals, melting-point 104°, insoluble in water but very soluble in alcohol. Sulphuric acid dissolved it with a dark red tint and caustic alkalis with a purple colour. Somewhat later Weyermann and Haffely (Annalen, 1850, 74, 226) suggested for santalin the formula C₁₅H₁₄O₅, though Franchimont and Sicherer again (Ber., 1879, 12, 14) considered the formula C₁₇H₁₆O₆ preferable. These latter authors who adopted a process very similar to that devised by Meier, could not obtain santalin in a crystalline condition, though this melted at 104-105°. Fused with caustic potash the amorphous product gave acetic acid, resorcinol, and probably also protocatechuic acid and catechol, and when heated with hydrochloric acid at 180° methyl chloride was evolved. Nitric acid gave oxalic acid and a yellow bitter substance, probably picric or styphnic acid, and when oxidised with permanganate, a crystalline substance having a strong odour of vanillin together with oxalic and acetic acids was produced. Weidel (Zeitsch. fur Chem., 1870, 6, 83) extracted the wood with boiling dilute alkali, neutralised the solution with hydrochloric acid and collected and dried the voluminous brickred precipitate. By long-continued extraction with ether he obtained from this two crystalline substances, santal, 2C₈H₆O₃, 3H₂O, which is colourless, and a bright red compound, C₁₄H₁₂O₄.

[---]

O'Neill and Perkin point out that the dyeing property of sanderswood seems to be due rather to deoxysantalin than to santalin, and although sanderswood is specially rich in colouring matter, it is astonishing how little of this comes into play during the dyeing process. Proof of this is obtained by dyeing wool with 60 per cent, of sanderswood and at the end of the operation employing the residual wood twice for dyeing fresh material. The first pattern possessed the usual colour, the second was pale pink, and the third was practically undyed, indicating that all the colouring matter soluble in water had then been removed. The woody matter, however, now yielded to alcohol 13,8 per cent, of extract compared with the 19,4 per cent. originally present, and this consisted of a dark red resinous mass and contained much santalin. Even, therefore, if it be presumed that all the soluble matter removed from the wood in the dye-bath is colouring matter (and this is improbable), it is evident that the larger proportion present therein, owing to its insoluble nature, remains undissolved and takes no part in the operation. Attempts to isolate Weidel's compounds (loc. cit.) from sanderswood were unsuccessful.

In addition to colouring matter, sanderswood contains two neutral compounds, Ptero-carpin and Homo-ptero-carpin, which were first isolated by Cazeneuve and Hugonueng (Comptes rendus, 1874; civ., 1722). These authors extracted a dried mixture of the wood and slaked lime with ether, and the product which remained on evaporating the ether was crystallised, first from alcohol and then fractionally so from carbon disulphide.

[---]

The Insoluble Red WoodsCHAPTER XVIII. Colouring Matters of Unknown Constitution.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

THE dyestuffs of this small group, Sanderswood, Barwood, Caliaturwood, Camwood, and Narrawood, all possess very similar dyeing properties, and owing to the sparing solubility in water of the resinous colouring matters which they contain, they are called "insoluble red" woods. They cannot, therefore, be made to yield the same type of commercial extract as is given by the soluble red woods, Brazilwood, Sapanwood, etc.

These dyewoods are chemically interesting in that the colouring matter present is substantive to wool, and thus, by merely boiling the material in an aqueous extract of the wood, or in a bath containing this in suspension, a brick-red shade is produced. It is remarkable, however, that though the tinctorial constituents of all these woods are readily soluble in alcohol, that the dye cannot now be removed from the fibre by this solvent, and it thus seems probable that it may exist thereon in the form of an acid calcium salt. Thus only by previously steeping the wool in concentrated hydrochloric acid, and subsequently washing, can the colouring matter be extracted by alcohol. The shades given by sanderswood, barwood, and caliaturwood are of a very similar character, camwood, on the other hand, giving somewhat bluer tones, and again according to dyers its colouring matter is more readily dissolved by water than that of the other dyewoods of this class.

Camwood
Chromium - Red-violet
Aluminium - Red
Tin - Blue-red
Iron - Violet

Sanderswood
Chromium - Brown-red
Aluminium - Orange-red
Tin - Red
Iron - Maroon

Though now practically unemployed in cotton dyeing, these woods, and especially barwood, were used considerably at one time in the production of a "mock Turkey-red". For this purpose the material was mordanted with a tin mordant, employing either stannate of soda or stannic chloride, and subsequently tannin or sodium carbonate as the fixing agent. On dyeing with barwood, a good bright red colour was thus produced, fast to milling but somewhat fugitive to light.

In wool dyeing, these woods still find a moderate application, usually in conjunction with other dyewoods, such as logwood and fustic, for the production of compound shades, and to a slight extent as a "bottom" in indigo dyeing. The general method of dyeing with them consists in first boiling the wool in a bath containing the wood, and then subsequently adding a solution of either potassium dichromate, ferrous sulphate or copper sulphate, the first operation being known as "stuffing" and the second, in which the shade becomes much browner, "saddening".

The colours given by these dyewoods are somewhat fugitive to light, and thus they have been almost superseded by the alizarins.

Toddalia aculeataCHAPTER XVII. Iso-Quinoline Group.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Toddalia aculeata (Pers.). This Indian plant, belonging to the rutaceæ, is a rambling shrub found in the sub- tropical Himalayas, in the Khasia mountains, and throughout the Western Peninsula and Ceylon.

The root bark is or was used in Madras as a yellow dyestuff, and it is also highly spoken of by various writers as one of the most valuable Indian medical products, possessing tonic, stimulant, and antipyretic properties. It was introduced into European medicine in 1771, and at one time enjoyed some celebrity under the name of "Lopez Root," but it has long since fallen into disuse. According to Brooks (Philippine Journal of Science, 1910, v., 442) this plant is common in the Philippines, but so far as is known is not used as a dye by the natives. The colouring matter it contains is berberine (Perkin and Hummel, Chem. Soc. Trans., 67, 413).

Euodia meliaefoliaCHAPTER XVII. Iso-Quinoline Group.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

This tree, belonging to the Rutacca, is found in China and Japan, where its bark is largely employed in dyeing and in medicine. It was formerly described by Loureiro as Ptero-carpus flavus, but this error was eventually corrected by P. W. Squire (Pharm. J., (3), 1888, 18, 785), who showed it to be really Evodia glauca, which is synonymous with E. meliaefolia. By qualitative tests, Martin, Tokio (Arch. Pharm., 1878, 13, 337) and Squire (loc. cit.) suspected the presence of berberine, and this colouring matter was subsequently isolated by Perkin and Hummel (Chem. Soc. Trans., 67, 415).

BarberryCHAPTER XVII. Iso-Quinoline Group.(Vain osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Barberry or berberry, Berberis vulgaris, is a compact bush which attains to a height of from 8-10 feet, and is found wild in Great Britain and throughout most parts of Europe and North America. The colouring matter present is berberine, and this, though occurring mainly in the bark, is also present in the stem and root of the plant.

Until recently a concentrated commercial extract of this material, known as "Barberry extract," was to be found on the market, and employed for dyeing silk and leather. It does not appear to have been at any time extensively used for these purposes, and is now apparently obsolete.

Barberry is, however, interesting, in that it contains the only natural basic dyestuff at present known, and may, in fact, be applied to fabrics in the same way as the artificial basic colouring matters. Silk and wool, for instance, may be dyed yellow by means of a faintly acidulated decoction of the material, preferably at from 50-60°, whereas for cotton, a tannin antimony mordant is necessary.

[---]

Numerous plants contain berberine, and though most of these have been or are used medicinally, their employment for dyeing has apparently been of rare occurrence. The following list embodies most of these:

Berberis aquifolium (Gordin, Arch. Pharm., 1902, 240, 146),
B. oetnensis (Perkin, Chem. Soc. Trans., 1897, 71, 1198), Cossinium fenestratum and Xanthorrisa aquifolia (Perrins, Annalen, 83, 276),
Hydrastis canadensis (Mahla, Amer. Chem. J., [2], 33, 843), Coptis aceta and C. trifolia, Chelidonium majus and Stylophorum diphyllum (Schlotterbeck, Amer. J. Pharm., 1902, 74, 584),
Evodia meliafolia and Toddalia aculeata (Perkin and Hummel, Chem. Soc. Trans., 67, 414),
Xanthoxylum clava Herculis (Chevallier and Pelletan, Journ. de Chim. Medicale, 1826, 2, 314),
yellow Assam wood or "Woodumpar" (Crookes' "Dyeing and Calico Printing"),
Coeloeline polycarpa (Stenhouse, Annalen, 66, 384; 69, 40), Archangelisa lemnis-cata (Becc.) and
Mahonia nepalensis (D.C.), (Brooks' Philippine Journ. of Science, 1910, v., 442).

For the commercial preparation of berberine the Hydrastis canadensis, which contains about 4 per cent, of the alkaloid, forms the best available material.

LitmusCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

This colouring matter is well known to the chemist, since white paper impregnated with its solution in a slightly acid or alkaline condition has long been employed, under the name of red and blue litmus-paper, to indicate the presence, in any solution, of alkalis or acids respectively. Alkalis change the colour of red litmus-paper to blue, acids turn blue litmus-paper red. In alkalimetry litmus tincture has, until recently, been the most generally adopted indicator. This use depends upon the fact that the free colouring matter of litmus is red, whereas its alkali salts are blue.

Commercial litmus has the form of small pale blue cubes, composed essentially of gypsum and chalk mixed with but comparatively little colouring matter, which is largely present in the form of a lake.

It is said to be prepared, chiefly in Holland, from various species of lichens, e.g. Lecanora tartarea, Roccella tinctoria, etc., the same, indeed, as are used in the manufacture of orchil (q.v.). Under the combined influence of ammonia and atmospheric oxygen the proximate principles contained in these lichens yield orceïn, the alkali salts of which are purple (orchil); but if potassium or sodium carbonate is present at the same time, the reaction proceeds further, and ultimately azolitmin (the colouring matter of litmus), the alkali salts of which are blue, is produced.

According to Gelis (J. Pharm. Chim., 24, 277; Revue Scient., 6, 50), litmus may be prepared as follows. Orchil-weed is ground and mixed with half its weight of potassium carbonate, and then repeatedly moistened with urine saturated with ammonium carbonate or with an aqueous solution of this salt; the mass soon acquires a brownish-red colour (three days), which gradually becomes purple "(twenty to twenty-five days), and finally blue (thirty days), yielding a litmus of the best quality in forty days. The pulpy mass is mixed with chalk and gypsum, then moulded in the form of cubes, and dried.

By modifying the action of air and ammonia upon orcinol, through the addition of sodium carbonate, De Luynes also succeeded in obtaining the colouring matter of litmus (Comptes rend., 59, 49; Dingl. poly. J., 174, 61 "; Chem. Zentr., 1865, 127; J., 1864, 551). A mixture of i part orcinol, 25 parts crystallised sodium carbonate, 5 parts water, and 5 parts ammonia solution, was heated to 60-80° for four to five days with frequent agitation. On diluting the blue solution thus obtained and acidifying slightly with hydrochloric acid, the colouring matter was precipitated. On washing and drying, it assumed a metallic lustre. It is sparingly soluble in water, but readily soluble in alcohol and in ether.

In making a litmus solution to be employed as indicator, the commercial litmus is extracted with boiling water, the filtered solution is slightly acidified with acetic acid, then carefully neutralised with ammonia, and boiled to expel any excess of the latter. Kept for any lengthened period in stoppered bottles, the solution becomes decolorised in consequence of a reductive fermentation; on exposure to air, however, the original colour is restored. This defect is prevented by saturating the solution with sodium chloride (Reichelt), (compare also Bellamy, J. Pharm. Chim., [v.], 18, 433). A dry litmus-extract may be prepared, according to Vogel, in the following manner (ibid., 45, 64, 70; Chem. News, 1864, 205). Twenty grams powdered commercial litmus are twice digested, each time with 150 c.c. cold distilled water. The second solution, which is alone employed, is divided into two equal portions, one of which is slightly acidified with nitric acid and then mixed with the other. The purplish solution thus obtained is evaporated to dryness on the waterbath, and the granular amorphous mass is kept in a stoppered bottle ready for dissolving in water when required.

For the employment and characteristics of litmus as an indicator, v. R. T. Thomson (J. Soc. Chem. Ind., 6, 198); also art. ACIDIMETRY, vol. i.; Marsh (Chem. News, 61, 2); Berthelot (Ann. Chim, Phys., [vii.], 25, 39); Ronde (Pharm. Zeit, 41, 736); Lescouer (Comptes rend., 123, 811); Lüttke (Zeitsch. anal. Chem., 31, 692); Foerster (ibid., 28, 428); Glaser (ibid., 38, 273).

Litmus exhibits a characteristic absorption spectrum. Ether extracts it from an acid solution, and forms a yellow liquid, whichabsorbs the more refrangible end of the spectrum to a point midway between D and E. If the solution is coloured blue by adding a drop of ammonia, an absorption-band is formed, commencing at D, where it is extremely black, and gradually diminishing to E. A blue aqueous commercial solution shows a well-marked absorption-band at D. Addition of acid changes the colour to red, the band at D disappears, and the spectrum now resembles that of cenolin, the colouring matter of red wine (A. H. Allen, Com. Org. Analysis, 325), (compare also Vogel, Praktische Spectralanalyse, 1877, 269).

Our knowledge of the chemistry of the colouring matters contained in litmus is very meagre. Gelis (J. Pharm. Chim., 27, 477) isolated from it several compounds in the following manner. After extracting commercial litmus with water, the insoluble residue is boiled with dilute caustic alkali and the filtered solution is precipitated with basic lead acetate. The blue precipitate is washed by decantation until it begins to dissolve and colour the wash-water. It is then decomposed with hydrogen sulphide, exposed to air until free from excess of H₂S, collected on a filter and digested with dilute ammonia to extract the colouring matter. On adding acid to the filtered solution the main portion of the litmus colouring matters is thrown down as a red flocculent precipitate. The filtrate from this contains a very small quantity of substance (α).

On extracting the dried red precipitate with ether and leaving the orange solution to spontaneous evaporation, it yields a bright red residue (β) containing crystalline needles. This product is insoluble in water, but readily soluble in alcohol, also in alkalis with a violet colour. The portion insoluble in ether is dissolved in alcohol, and on allowing the blood-red solution to evaporate spontaneously it yields a large quantity of a reddish-purple product (y) having a bronze lustre. This represents the colouring matter most abundant in litmus.

The residue, which is insoluble in water, in alcohol, and in ether, contains another product (δ) which is soluble in alkalis, from which it may be precipitated by acids. The three products β, γ, and δ, appear to contain nitrogen.

An examination of litmus was made in 1840 by Kane (Royal Soc. Trans., 1840, 298; Ann. Chim. Phys., [iii.], 2, 129; Annalen, 39> 57 J J- Pharm. Chim., 1841, 569), who isolated from it the chief and characteristic colouring matters azolitmin and erythrolitmin, together with erythroleïn and spaniolitmin.

According to Kane, finely powdered commercial litmus is extracted with boiling water. Most of the colouring matter remains in the form of an insoluble lake in the residue, to which hydrochloric acid is added till effervescence ceases and the mixture is strongly acid. The insoluble matter interspersed with liberated colouring matter is collected on a filter, washed free from acid, dried, and extracted with boiling alcohol. The alcoholic solution is filtered from an insoluble reddish-brown mass (impure azolitmin) and then evaporated to dryness, and the residue is digested with warm ether until it becomes no longer coloured. On distilling the filtered ethereal solution, erythroleïn is left as a purple semi-fluid oily substance. That portion of the alcoholic extract which is insoluble in ether consists of erythrolitmin.

The above-mentioned impure azolitmin is purified, either by dissolving it in a large quantity of boiling water and evaporating the solution to dryness, or by dissolving it in very dilute ammonia, evaporating the solution to dryness, neutralising any residual ammonia by dilute hydrochloric acid, and washing with alcohol until free from ammonium chloride and excess of hydrochloric acid. The residue represents purified azolitmin.

The colouring matter contained in the deeply coloured solution obtained in the first instance by boiling the commercial litmus with water and filtering, is isolated as follows. The solution is precipitated with neutral lead acetate, the purple precipitate thus obtained is well washed, suspended in water, and decomposed with hydrogen sulphide. The mixture of lead sulphide and liberated colouring matter thus obtained is well washed and digested with warm dilute ammonia; the filtered deep -blue solution is evaporated to dryness, the residue is moistened with hydrochloric acid, washed free from ammonium chloride and any excess of hydrochloric acid, with warm alcohol. The residual deep brownish-red powder consists usually of nearly pure azolitmin, more rarely of spaniolitmin, a substance very similar to azolitmin, but which does not contain nitrogen.

Since spaniolitmin occurs so rarely in litmus, and erythrolein is coloured reddish-purple and not blue by alkalis, Kane considers azolitmin and erythrolitmin to be the essential colouring matters of litmus, in which they are combined with ammonia, potash, and lime, and mixed with a considerable quantity of chalk, gypsum, etc.

Azolitmin is a deep brownish-red amorphous powder, insoluble in alcohol and sparingly soluble in water, but readily soluble in alkaline solutions with a pure blue colour. Its ammoniacal solution gives with metallic salt solutions blue or purple precipitates according as they are more or less basic in character. Kane's formula for azolitmin is C₉H₁₀NO₆, but Gerhardt considers it is best represented by C₇H₇NO₄. It differs from all the other colouring matters isolated from litmus by containing nitrogen. Gerhardt considered it to be derived from orcinol, possibly in accordance with the following equation: C₇H₆O₂ + NH₃ + 3O = C₇H₇NO₄ + H₂O, or from orcein thus, C₇H₇NO₃ + O = C₇H₇NO₄.

If the percentage composition assigned to this substance is correct, the explanation of the part played by the necessary alkaline carbonate in the manufacture of litmus may be that it facilitates and increases the oxidation of the orcinol, so that the orcein at first formed is changed into azolitmin (Gerhardt, Ch. Org., 3, 816).

Scheitz (Zeitsch. anal. Chem., 1910, 49, 736) has isolated from litmus a blue colouring matter distinct from azolitmin in quantity equivalent to 1,5 per cent, of the weight of the purified material. It consists of a bright brown powder soluble in formic acid, pyridine, and ammonia, forming a bluish-violet solution with the last-named solvent. It absorbs ammonia gas with production of a dark blue ammonia compound, which dissolves in water to a reddish solution. This ammonia compound is a more delicate indicator than the corresponding derivative of azolitmin.

Erythrolitmin, which also constitutes one of the most important ingredients of litmus, is a bright-red powder, sparingly soluble in water and in ether. It is abundantly soluble in alcohol, from which it may be crystallised in the form of dark-red granular crystals. In strong caustic potash it dissolves with a blue colour. With ammonia it forms a blue compound which curiously enough is totally insoluble in water. With metallic salts it forms lakes of a fine purple colour. According to Kane its formula is C₁₃H₂₂O₆, and he considers it to be an oxidation product of his erythroleic acid (C₁₃H₂₂O₄ ) obtained from orchil.

Erythroleïn forms a crimson semi-fluid mass, almost insoluble in water, soluble in ether and in alcohol with a red colour, and in ammonia with a purple colour. With metallic salts it gives purple lakes. Kane gives its formula as C₁₃H₂₂O₂. Its general properties are very similar to those of the above-mentioned erythroleic acid.

Spaniolitmin occurs but rarely in litmus, hence its name. It is a bright-red substance, insoluble in alcohol and in ether, and very sparingly soluble in water. It dissolves in alkalis with a blue colour and gives lakes very similar to those of azolitmin. Kane's formula for it is C₉H₇O₈.

Under the influence of hydrogen sulphide, the colouring matters of litmus are decolorised, Kane's idea being, that a colourless hydrogen sulphide compound is thus formed (v. also Malaguti, Ann. Chim. Phys., (iii.), 37, 206; Vogel, J. pr. Chem., (ii.), 16, 311). Nascent hydrogen, and other reducing agents such as ferrous and stannous oxide, etc., also decolorise them by reduction in the ordinary manner. Azolitmin thus yields colourless leucazolitmin, which, however, rapidly oxidises and becomes coloured on exposure to air. If stannous chloride is added to an ammoniacal solution of azolitmin, purple-coloured stannous -azolitmin is precipitated; if this is boiled with slightly acidulated water there is formed the colourless compound of stannic oxide with leucazolitmin, which, if exposed to air, changes into the bright scarlet stannic-azolitmin.

Deoxidising agents such as sulphurous acid and sulphites do not decolorise the colouring matters of litmus.

Azolitmin and erythrolitmin, suspended in water and submitted to the action of chlorine gas, are decolorised and give yellow chlorine derivatives, chlorazolitmin and chlorerythrolitmin, substances insoluble in water, but soluble in alcohol, ether, and in alkalis.

In his earliest memoir, Kane (Annalen, 36, 324) mentions that on heating the colouring matters of litmus mixed with chalk or gypsum, a red vapour is given off which condenses in the form of crystalline scales (atmérythrin) soluble in alcohol. When heated alone, this substance is not produced. Although Kane makes no subsequent mention of this body it is possible that it was indirubin or even indigotin, since at a later date Wartha (Ber., 9, 217) states that he found some samples of litmus to contain indigotin, recognisable by the violet vapour given off on heating a few cubes of the commercial product in a test tube. Its presence may have been due to the use of urine containing indoxyl in the preparation of the litmus.

Wartha (loc. cit.) gives the foliowingjesults of his examination of litmus. The commercial product is well shaken up with alcohol; the filtered purple solution thus obtained has a green fluorescence, and exhibits in the spectroscope a characteristic absorption band in the green with an almost total absorption of the violet end. The colouring matter (1) itself is obtained on evaporating the solution.

The litmus residue insoluble in alcohol is digested for twenty-four hours with distilled water, and the filtered deep- coloured solution is evaporated to dryness. The extract thus obtained is repeatedly treated with absolute alcohol containing a little glacial acetic acid and again evaporated, so that all traces of water may be removed, and there finally remains a brown powdery mass. On extracting this with absolute alcohol, a large quantity of a scarlet substance (b) is dissolved. It is similar to orcei'n and dissolves in ammonia with a reddish-purple colour. That portion of the brown powder which is insoluble in the acidified alcohol is dissolved in water, the filtered solution is evaporated to dryness, and the residue is repeatedly washed with absolute alcohol and evaporated in order to expel all traces of acetic acid. The residual brown powder, which is very soluble in water, with a reddish-brown colour, but insoluble in alcohol and in ether, is the purified and extremely sensitive colouring matter of litmus (c). Its alkaline solution is blue, its aluminium and tin lakes are violet, and its calcium and barium lakes blue. It appears to be very similar to Kane's azolitmin, but it is said not to contain nitrogen. The yield of these various colouring matters is as follows: (a) 2,3 per cent., (b) 3,4 per cent, (c) 5,7 percent. (Mitchell, Chem. News, 1876, 140).

An examination of the colouring matters of litmus was also made by Rochleder and Skraup (Wien. Anz., 1874, 118; Chem. Zentr., 1874, 424). Other references are Magner, J. Pharm. Chem., 12, 418; Desfosses, ibid., 14, 487; Peretti, ibid., 14, 539.

Of interest also in connection with this subject is the fact that when ethyl-amino-orsellinic acid is oxidised by air in alkaline solution it yields an orange-coloured dye possessing basic properties (Heinrich and Dorschky, Ber., 1904, 37, 1416).

A peculiar blue colouring matter similar to litmus, and called tournesol en drapeaux, has long been manufactured at Grand-Gallargues, Departement du Gard, France, from the Croton tinctorium belonging to the Euphorbiaceæ. Coarse linen cloth is steeped in the deep bluish-green sap expressed from the berries and the tops of the plant, then dried quickly in the open air, and exposed for one to one and a half hours between layers of straw to the ammoniacal vapours of lant or horse-dung (aluminadon) care being taken not to submit them to this influence too long. The cloth thus acquires a deep blue colour. It is then steeped in the sap a second time and dried in air till it acquires a purple or dull green. These blue cloths are or were used by the Dutch farmers for making an infusion with which to impart a red colour to the outside of their cheese, the blue being changed to red by the lactic and butyric acids of the cheese.

According to Joly (Ann. Chim. Phys., [iii.j, 6, in) the colouring matter pervades the entire plant and is readily extracted therefrom by water heated to 50-60°. On being evaporated, an azure-blue resinous mass remains. Acids change the blue colour of its aqueous solution red, and this blue is not restored by alkalis, the colour becoming thereby rather greenish. It is, therefore, probably quite distinct from the colouring matter of litmus, and is, indeed, more similar to the blue colouring matter which can be extracted from another plant belonging to the Euphorbiacea} viz. Mercurialis perennis.

Archil or Orchil.CHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Archil or Orchil (Orseille, Fr.; Orseille, Ger.; Oricello, It.) appears in commerce in three forms: (1) as a pasty matter called archil; (2) as a mass of a drier character, named persio; and (3) as a reddish powder called cudbear. It is obtained from various lichens of the genus Roccella, growing on the rocky coasts of the Azores, the Canaries and Cape de Verd Isles, also of the Cape of Good Hope, Madeira, Corsica, Sardinia, etc., and from Ochrolechia tartarea, growing in Sweden and Norway. None of these lichens contains the colouring matters ready formed, but they contain certain colourless acids of the type of lecanoric acid, derivatives of orcin, into which they can be readily converted. Thus, lecanoric acid (1) gives first orsellinic acid (2) and subsequently orcin (3) according to the following scheme (see under LECANORIC ACID): [KUVA PUUTTUU]

Orcin itself, when acted upon by air and ammonia, changes into a purple substance called orcein, which is the name applied to the colouring matters of archil (Robiquet, Ann. Chim. Phys., [2], 47, 338).

Finely powdered orcin is placed in. a thin layer under a bell jar, together with a beaker containing strong ammonia solution. As soon as the substance has become brown coloured, it is removed and exposed to air for some time. It is then dissolved in very dilute ammonia solution, reprecipitated with acetic acid, and dried. According to Gerhardt and Laurent, orcein has the composition C₁₄H₇NO₆ (Ann. Chim. Phys., [3], 24, 315), but more recent researches indicate that it is a mixture of substances. Liebermann, for instance (Ber., 7, 247; 8, 1649), considers that by this reaction three colouring matters are produced, having respectively the formulæ (a) C₁₄H₁₃NO₄; () C₁₄H₁₂N₂O₃; and (c) C₁₄H₁₂N₂O₃.

Zulkowski and Peters (Monatsh., 11, 227) allowed orcin to remain in contact with ammonia for two months, and from the product isolated three substances:

(a) Red orcein, C₂₈H₂₄N2O₇, the main product, which appears to be formed according to the following equation:
4C₇H₈O₂ + 2NH₃ + 6O = C₂₈H₂₄N₂O₇ + 7H₂O
It is a brown crystalline powder, soluble in alcohol with a red colour, and in alkaline solutions with a blue-violet tint.

(b) A crystalline yellow compound, C₂₁H₁₉NO₅, which is accounted for as follows: 3C₇H₈O₂ + NH₃ + 3O = C₂₁H₁₉NO₅ +4H₂O

(c) An amorphous product similar to litmus.

These substances can be prepared much more rapidly by the addition of hydrogen peroxide to an ammoniacal solution of orcin.

There can be no doubt that this reaction proceeds in several stages, and that the character of the product varies according to the duration of the process. This is well known to manufacturers, whocan prepare at will a blue or a red orchil. The constitution of these colouring matters has not yet been determined, but in view of the circumstances by which they are produced, it is most probable that they are members either of the oxazine or oxazone groups.

Orchil was originally prepared from the lichens by means of stale urine, which supplied the necessary ammonia, but ammonia solution is now exclusively employed. The older methods have, however, been greatly improved, and in the place of barrels the operation is carried out in large horizontal or vertical cylinders fitted with stirrers, and suitable openings for the admission of air.

In such an apparatus the weed is digested with about three times its weight of ammonia solution at 60° for from three days to one week, the admission of air being regulated according to the judgment of the manufacturer. The first product of the reaction has a blue colour, and if the process be stopped at this point, there is formed the dyeware known as blue orchil. On the other hand, if the action of the air and ammonia is allowed to proceed further, red orchil is obtained. These orchil pastes when dried and finely ground constitute the product known as cudbear.

Bedford (Ger. Pat. 57612, 1889) blows air or oxygen through the ammoniacal mixture, which, especially in the latter case, materially shortens the process. The apparatus employed is erected vertically, and by an ingenious arrangement of projecting shelves, the edges of which are turned down, a considerable quantity of the air or oxygen is entrapped, and exerts therefore a more powerful oxidising effect.

Orchil liquor is prepared by extracting the lichens with boiling water, concentrating the extract to from 8-10° Tw., and submitting this to the action of air and ammonia; whereas orchil extract is produced by the extraction of orchil paste itself.

In former times archil and cudbear were frequently adulterated with magenta, certain azocolours, extracts of logwood, brazilwood, etc.; but as the importance of these dyestuffs has now very greatly diminished, such a contamination is at the present time of rare occurrence.

Archil and its preparations are substantive colouring matters, which dye well in a neutral bath, but have the useful property of behaving nearly as well under slightly acid or lightly alkaline conditions. Even colours of considerable intensity are produced from it without difficulty, but unfortunately these are not fast to light. Wool is dyed in a neutral bath, or with addition of a trace of sulphuric acid, and silk is dyed in the presence of soap solution, acetic acid being sometimes added. Archil is not applied to cotton.

Archil was at one time employed to a large extent for "bottoming" indigo, that is to say, the fabric was first dyed with archil and subsequently with indigo. The reverse process, known as "topping," has again been considerably in vogue. Cudbear and archil are also used to a limited extent in conjunction with other dyestuffs for the production of compound shades. White wines are sometimes coloured with archil, but its presence can be detected by precipitating with lead acetate and extracting with amyl alcohol, when a red colour indicates the presence of archil or magenta. The addition of a little hydrochloric acid changes the colour to yellow if magenta be present, but does not alter it if archil is the adulterant (Haas, Zeitsch. anal. Chem., 20, 869; J. Soc. Chem. Ind., 1, 119).

Barbatic acidCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Barbatic acid, C₁₉H₂₀O₇, was first isolated from the lichen Usnea barbata by Stenhouse and Groves (Chem. Soc. Trans., 1880, 37, 405), in which it occurs in conjunction with usnic acid. Zopf (Annalen, 1897, 297, 271) found barbatic acid in the Usnea longissima, in the Electora ochroleuca (ibid., 1899, 306, 282), and in the Usnea dasypoga (ibid., 1902, 324, 39); Hesse (J. pr. Chem., 1898, ii., 57, 232) describes its presence in the Usnea longissima, Usnea barbata, and Usnea ceratina. Hesse (loc. cit.) originally considered that barbatic acid had the composition C₂₂H₂₄O₈, and described potassium barium and copper salts and an ethyl ester, melting-point 132°, which apparently established this formula, but in a later paper (J. pr. Chem., 1903, ii., 68, i) he adopted Stenhouse and Groves' formula, C₁₉H₂₀O₇. The sodium salt, C₁₉H₁₉O₇Na, 2H₂O, crystallises in straight-sided leaflets (compare also Zopf, 1902, 789). The action of acetic anhydride on barbatic acid leads to the formation of a compound which is probably the lactone of acetylbarbatic acid; this melts at 250° and on recrystallisation from acetic anhydride yields acetylbarbatic acid, C₁₉H₁₉(C₂H₃O)O₇, melting-point 172°. By the hydrolysis of barbatic acid with aqueous alkalis betorcinol and rhizoninic acid are formed. Barbatic acid crystallises in colourless needles, melting-point 184° (Hesse, J. pr. Chem., 1906, (2), 73, 113).

AtranorinCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Atranorin, C₁₉H₁₈O₈, is present in the lichens Evernia vulpina, E. prunastri, E.furfuracea, Lecanora atra, L. sordida, Parmelia perlata, P. physodes, P. tinctorium, Physcia stellaris, Xanthoria parietina, Cladonia rangiformis, Stereocaulan vesuvianum and others. It forms colourless prisms, melting-point 195-197° C. (Zopf), 187-188°C. (Hesse), easily soluble in hot chloroform, soluble in alkalis with a yellow colour.

According to Paternò, by heating with water to 150°, atranorin gives physciol (methyl-phloroglucinol) and atraric acid (betorcinolcarboxylic acid methyl ester), and these substances are also obtained when atranorin is heated with acetic acid in a sealed tube (Hesse).

[---]

ErythrinCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Erythrin, erythric acid, erythrinic acid, erythroiecanoric acid, C₂₀H₂₂O₁₀H₂O, is a constituent of most lichens from which archil is prepared. It was discovered by Heeren (Schweigger's Journ. f. Chem., 59, 513) in Rocella tinctoria (D.C.), from which lichen, and several others of the same genus, it may be extracted by boiling water, or better, with milk of lime (cf. also Kane, Stenhouse, and Hesse (loc. cit.); Schunck, Annalen, 61, 69; De Luynes, Ann. Chim. Phys., [4], 2, 385; Menschutkin, Bull. Soc. chim., [2], 2, 424).

The method adopted by Stenhouse to prepare this substance from the Rocella fuciformis is as follows (Annalen, 68, 72, and 149, 290): Three pounds of the lichen are macerated for twenty minutes in a milk of lime made by shaking ½ lb. of lime in 3 gallons of water, and the product filtered by means of a bag filter. The clear liquid, as it passes through, is immediately precipitated with hydrochloric acid, as prolonged contact with the lime decomposes part of the erythrin. The crude erythrin collected on bag filters is freed from acid and calcium chloride by stirring it up once or twice with a considerable quantity of water and again collecting.

[---]

Evernic Acid and Everninic acidCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Evernic acid, or lecanoric acid monomethyl ether, was first isolated by Stenhouse from the Evernia prunasti (Annalen, 68, 83), and has been found also by Hesse (Ber., 1897, 30, 366) to exist in the Ramalina pollinaria (compare also Zopf, Annalen, 1897, 297, 271).

The lichen is extracted with diluted milk of lime, the extract neutralised with acid, the precipitate collected, dried, and digested with a little boiling alcohol. The hot alcoholic liquid, treated with its own volume of water, deposits crystals of evernic acid (Stenhouse).

[---]

Lecanoric acidCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Lecanoric acid (Diorsellinic acid), C₁₆H₁₄O₇, H₂O, was first described by Schunck under the name of "lecanorin,"and was isolated by him from various species of the Lecanora and Variolaria lichens. It is also present in some quantity in the Rocella canariensis, R. portentosa, R. sinensis, and Parmelia perlata (loc. cit.), and, according to Hesse (Annalen, 139, 24), is best isolated by the following method, which is a modification of that originally devised by Schunck. The finely divided lichen is extracted with ether, the extract evaporated, and the greenish-white crystalline residue treated with lime water. The solution, when neutralised with acid, gives a precipitate of lecanoric acid, which is collected and crystallised from alcohol. In case the product is not quite pure it is treated with ether, which dissolves the acid, but not the impurity.

Lecanoric acid crystallises in colourless needles, melting-point 166° (Hesse, Ber., 37, 4693), the solutions of which possess an acid reaction. With alcoholic ferric chloride it gives a dark purple coloration, and with dilute calcium hypochlorite a blood-red liquid, which, according to Hesse, is characteristic, and can be used to distinguish this substance from the known lichen acids.

[---]

Orsellinic acid.CHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.(Osa artikkelista)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Orsellinic acid, C₈H₈O₄, H₂O, was first prepared by Stenhouse (Annalen, 68, 61) by digesting lecanoric acid with boiling baryta water, and can also be produced from erythrin in a similar manner. According to Hesse (ibid., 139, 35), the solution of erythrin in baryta water is heated on the steam-bath until a sample of the product no longer yields a gelatinous precipitate when neutralised with hydrochloric acid. The liquid is then acidified, and the orsellinic acid, which separates on standing, is crystallised from alcohol or acetic acid.

Orsellinic acid crystallises from dilute acetic acid in needles with 1H₂O. When heated, it melts at 176° with evolution of carbon dioxide and formation of orcin, and is evidently an orcin carboxylic acid.

Ethyl orsellinate, C₁₀H₁₂O₄, colourless leaflets, melting-point 132°, is produced when erythrin is boiled for several hours with alcohol (Stenhouse, loc. cit.), and can be prepared in an identical manner from lecanoric acid (Schunck, Annalen, 54, 265).

Methyl orsellinate, C₉H₁₀O₄ (Schunck, loc. cit., and Stenhouse, loc. cit.), and isoamyl orsellinate, C₁₃H₁₈O₄ (Stenhouse; Hesse, Annalen, 139, 37), melting-point 76°, have also been obtained.

[---]

LichensCHAPTER XVI. Lichens, Lichen acids, and Colouring Matters Derived Therefrom.

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Many species of lichens have been employed from the earliest times in medicine, dyeing, and as foodstuffs ("Mémoires sur 1'utilité des lichens," par Hoffmann, Amoreux et Willemet, Lyon, 1787). From about the year 1300, certain species have been utilised for the production of the purple dyestuff "archil" or "orchil," since, as shown by modern researches, they contain colourless principles, derivatives of orcin, which under the influence of ammonia and atmospheric oxygen yield the purple colouring matter known as orcein (v. archil). Under the name of Crottle or Crotal, with various descriptive prefixes, several species have been, and still are to a very limited extent, directly applied in dyeing buff and brown colours on homespun yarn in the Highlands of Scotland, Wales, etc. Those lichens, e.g. Iceland moss (Cetraria islandica, Ach.), which serve as foodstuffs, contain a starch-like substance termed lichenin, which is capable of conversion into glucose.

Our earlier chemical knowledge of the constituents of many of these lichens is mainly due to the work of Knop, Rochleder, Heldt, Schunck, Schmidt, Stenhouse, Stenhouse and Groves, and Weppen, whereas for the later very numerous investigations we are chiefly indebted to the chemists Oswald Hesse and Wilhelm Zopf. As a result, a very large number of new compounds have been isolated and described, the constitutions of which in most cases, however, are as yet undecided. On the other hand, considerable advance has been made as regards the exact structure of some of the more common constituents, viz. atranorin (atranoric acid), barbatic acid, evernic acid, erythrin (erythric acid), lecanoric acid, and ramalic acid, and the chemistry of these substances is dealt with under their special headings.

As the work of Hesse (H.) is mainly to be found in the Journal für praktische Chemie, and that of Zopf (Z.) in the Annalen, to avoid frequent repetition the year only of the papers published in the journals is noted below.

Trachylia tigillaris, Fr. (Acolium tigillare; Calicium tigillare, Cyphelium tigillare), rhizocarpic acid, C₂₈H₂₀O₇ (H.), melting-point 177-178°, and acolic acid (H. 1900).

Acarospora chlorophana, rhizocarpic acid, pleosidic acid, C₁₇H₂₈O₄, melting-point 131-132° (Z. 1903).

Alectoria implexa, Nyl. (A. cana), zeorin, salazinic acid (Z. 1898). A. ochroleuca, usnic acid, C₁₈H₁₆O₇, and barbatic acid (Z. 1899). A. sarmentosa, usnic acid (Z. 1900). A. jubata, var. implexa, salazinic acid, alectoric acid, C₂₈H₂₄O₁₅, melting-point 186°. A. articulata d-usnic acid, usnaric acid, C₂₈H₂₂O₁₅, melting-point 240-260°. A. canariensis, d-usnic acid, usnaric acid (H. 1902). A. implexa, atranorin (H. 1906).

Anaptychia ciliaris, atranoric acid (atranorin). A. speciosa, atranorin, zeorin, C₅₂H₈₈O₄ (Z. 1895 1897).

Aspicilia calcarea, erythric acid, oxalic acid, aspicilin, melting-point 178.5° (H. 1900). A. gibbosa, aspicilic acid, melting-point 150° (H. 1904).

Baeomyces roseus, an acid, melting-point 180° (H. 1898).

Biatora lucida, rhizocarpic acid, C₂₈H₂₀O₇, atranorin (Z. 1897; H. 1907); no usnic acid (cf. Knop, 1843). B. mollis, diffusic acid (Z. 1905). B. Lightfootii, l-usnic acid (Z. 1906). B. grandulosa, gyrophoric acid, C₁₆H₁₄O₇ (Z. 1906).

Blastenia arenaria (Callopisma erythrocarpa), phytosterol, blasterin, melting-point 170° (H. 1898). B. arenaria, atranorin, gyrophoric acid, C₁₆JH₁₄O₇ (H. 1898). B. Jungermanni, parietin (Z. 1906).

Calydum crysoctphalum, vulpic acid (H. 1898; Z. 1895). C. chlorinum or chlorellum, vulpic acid (Z. 1895); pulvic acid and traces of leprarin, C₁₉H₈O₉ (Kassner, Arch. Pharm., 239, 44; H. 1900). C. flavum, chyrsocetraric acid, C₁₉H₁₄O₆ (H. 1900). C. Stenhammari, calycin, C₁₈H₁₂O₅ (Z. 1895).

Callopisma flavovirescens, chrysophanic acid, physcion, C₁₈H₁₂O₅ (H. 1902). C. vitellinum, calycin (Z. 1895); callopismic acid and mannitol (Z. 1897).

Rhizocarpon oreites, A. Zahlbr. (Catocarpus oreites), rhizocarpic acid, C₂₈H₂₀O₇, psoromic (parellic) acid, C₂₁H₁₆O₉ (Z. 1905).

Cetraria cucullata (Platysma cucullatum), protolichesteric acid, C₁₈H₃₂O₅ (Z. 1902). C. chlorphylla, protolichesteric acid and atranorin (Z. 1902). C. complicata, protocetraric acid, C₃₀H₂₂O₁₅, l-usnic acid, and atranorin.

Cetraria islandica contains starch not deposited in granules, but uniformly distributed among the cells (lichenin). The lichenin, which is convertible into sugar, is present in such large quantity that this lichen can be used for food (Schmidt, Annalen, 51, 29). There is also said to be present cetraric acid, lichenstearic acid (Knop and Schaedermann, Annalen, 55, 114), protocetraric acid, and proto-#- lichesteric acid (Z. 1902; H. 1903 and 1904), α-lichenostearic acid, C₁₈H₃₀O₅ (melting-point 122-123°), β-lichenostearic acid, C₁₈H₃₀O₅ (melting-point 121°), γ-lichenostearic acid, C₁₈H₃₀O₅ or C₁₉H₃₂O₅ (melting-point 121-122°), paralichenostearic acid, C₂₀H₃₄O₅, dilichenostearic acid, C₃₆H₆₀O₁₀, and cetraric acid, C₂₆H₂₀O₁₂ (H. 1898).

C. nivalis, usnic acid (Z. 1904). C. stuppea, protolichesteric acid (Z. 1904). C. aculeata or Cornicularia aculeata, protolichesteric acid (Z. 1 904); lichenin and lichenic (fumaric) acid. C. pinastri, pinastric acid, C₁₀H₈O₃ (Z. 1895). C. glauca (Platysma glaurum), lichenin (Berzelius). C. juniperina, chrysocetraric acid, C₁₉H₁₄O₆, usnic and vulpic acids (H. 1898). C. pinastri, chrysocetraric, usnic and vulpic acids (H. 1898; Z. 1899). C.fahlunensis, cetraric acid (Z. 1898).

Candelaria concolor, callopismic acid or ethyl-pulvic acid, C₂₀H₁₆O_5, dipulvic acid, C₃₂H₂₂O₅ (Z.); calycin, and stictaurin, C₁₈H₁₂O₅ (H.; Z. 1899). According to Hesse, 1898, dipulvic acid is a mixture of calycin and pulvic anhydride. C. vitellina, stictaurin (Z. 1899), calycin and pulvic anhydride (Z. 1899).

Cladina silvatica, usnic acid and cetraric acid (Z. 1898). C. alpestris, usnic acid (Z. 1898). C. rangiferina, cetraric acid and atranorin (Z. 1898) and usnic acid (H. 1898). C. pyxidata, parellic acid (H. 1898). C. coccifera, cocellic acid, C₂₂H₂₀C₇ (H. 1898). C. uncialis, d-usnic and thamnolic acids, C₂₀H₁₈O₁₁ (Z. 1902).

Cladonia amaurocraea, usnic acid (Z. 1898). C. alcicornis, usnic acid (H. 1902). C. deformis, usnic acid (Z. 1900). C. cyanipes usnic acid (Z. 1900). C. Floerkeana, cocellic and thamnolic acids (H. 1900). C. rangiformis, atranorin, rangiformic acid C₂₀H₃₃O₅.OMe (H. 1898). C. uncinata (no usnic acid, see Knop, Annalen, 1844, 49, 120); but uncinatic acid, C₂₃H₂₈O₉ (H. 1900). (7. destricta (C. uncialis), usnic acid and starch (Knop, ibid., 119); l-usnic acid (Salkowski, Annalen, 1901, 319, 391). C. incrassata, l-usnicacid (S.). C. glauca, squamatic acid (Z. 1902). C. strepsilis, thamnolic acid and strepsilin (Z. 1903). C. thamnolis, thamnolic acid, C₂₀H₁₈O₁₁, and strepsilin. C. destricta, l-usnic acid (Z. 1903); l-usnic and squamatic acids and cladestin (H. 1904). C. macilenta, usnic acid and starch (Knop, loc. cit.); rhizonic acid (Z. 1903). C. squamosa, var. ventricosa, squamatic acid (Z. 1904). C. squamosa, var. denticollis, squamatic acid (Z. 1907). C. fimbriata, var. simplex, fumaroprotocetraric acid and fimbriatic acid (Z. 1907). C. fimbriata, var. cornuto-radiata, fumaroprotocetraric acid (Z. 1907). C. pityrea, var. cladomorpha, fumaroprotocetraric acid (Z. 1907). C. silvatica, var. condensata, l-usnic acid (Z. 1907). C. verticillata, var. subcervicornis, fumaroprotocetraric acid (Z. 1907), atranorin and cervicornin. C. chlorophœa, fumaroprotocetraric acid. C. gracilis, var. chordalis, fumaroprotocetraric acid (Z. 1907). C. crispata, var. gracilescens, squamatic acid (Z. 1907). C. coccifera, cocellic acid, C₂₀H₂₂O₇ (H. 1895). C. incrassata, l-usnic acid (Z. 1905). C. rangiferina usnic acid (Rochleder and Heldt, Annalen, 48, 2); lichenin (Schmidt, ibid., 51, 29); cladonic acid (β-usnic acid), C₁₈H₁₈O₇ (Stenhouse, ibid. 155, 58); d-usnic acid (no l-usnic) and silvatic acid, CO₂Me.C₁₈H₂₄O₃.COOH (H. 1907); atranorin and fumaroprotocetraric acid (Z. 1906). C. rangiferina, var. vulgaris, atranorin and protocetraric acid (H. 1898). C. rangiferina, var. silvatica, d-usnic acid (Z. 1906); usnic and protocetraric acids (H. 1898). C. pyxidata, lichenin (Schmidt, Annalen, 51, 29); emulsin (Hérissey, J. Pharm. Chim., 1898, [vi.], 7, 577).

Cornicularia aculeata, rangiformic acid (H. 1902).

Chiodecton sanguineum (C. rubrocinctum), chiodectonic acid, C₁₄H₁₈O₅

Cyphelium trichiale, var. candelare, calycin (Z. 1906).

Darbishirella gracillima, parellic acid (H. 1898).

Dendographa leucophœa, protocetraric acid (H. 1898); erythrin and orcinol (Ronceray, Bull. Soc. chim., 1904, [iii.], 31, 1097).

Dimelaena oreina, zeorin and usnic acid (Z. 1897).

Diploicia canescens (Catolechia canescens), diploicin, melting-point 225, catolechin, melting-point 214-215°, and atranorin (Z. 1904).

Diploschistes scruposa, diploschistessic acid, C₁₅H₁₆O₇ (Z. 1906).

Endorcarpon miniatum (a) vulgare, phytosterol and an acid (H. 1898).

Evernia divaricata, divaricatic acid, C₂₁H₂₂O₆.OMe (H. 1900), and usnic acid (Z. 1897); no usnic acid (H.). E. furfuracea, usnic acid (Rochleder and Heldt, Annalen, 48, 9); no usnic acid, but erythric acid (Z. 1897), or rather olivetoric acid, C₂₇H₃₆O₈ (Z. 1900) physodic acid, physodylic acid, C₂₃H2₂₆O₈, and fureverninic acid (H. 1907); atranorin, evernuric acid, C₂₂H₂₄O₈, and furevernic acid, but no erythric or olivetoric acids (H. 1906); emulsin (Hérissey, J. Pharm. Chim., 1898, [v.], 7577). E. prunastri, evernic acid, atranorin (Z. 1897); evernic acid, usnic acid and atranorin and chrysocetraric acid (H. Annalen, 1895), C₁₉H₁₄O₆. E. thamnodes, divaricatic acid, usnic acid (Z. 1897; H. 1900). E. vulpina, vulpic acid and atranorin (H.). E. illyrica (Dalmatia), divaricatic acid and atranorin (Z. 1904). E. ochroleuca, usnic acid (Knop, Annalen, 49, 122).

Everniopsis Trulla, salazinic acid and atranorin (Z. 1897).

Gasparrinia medians (Physcia medians) calycin, rhizocarpic acid (H. 1898); pulvic lactone (H. 1903). G. sympagea, parietin (Z. 1905). G. elegans (Physcia elegans), physcion (H. 1898). G. murorum, physcion (H. 1898). G. decipiens, physcion (H. 1898). G. cirrhochroa, chrysophanic acid (Z. 1897).

Graphis scripta, salazinic acid (H. 1900).

Gyalolehia aurella, calycin (Z. 1895), callopismic acid (Z. l897)> stictaurin (Z. 1899).

Umbilicaria pustulata (Hoffm.). (Gyrophora pustulata), gyrophoric acid, C₃₆H₃₆O₁₅ (Stenhouse, Annalen, 70, 218), C₁₆H₁₄O₇ (H.). G. hirsuta, gyrophoric acid (Z. 1898). G. deusta, gyrophoric acid (Z. 1898). G. polyphylla, umbilicaric acid, C₂₅H₂₂O₁₀ (Z. 1898); umbilicaric acid and gyrophoric acid (H. 1898, 1901). G. hyperborea, umbilicaric acid (Z. 1898). G. deusta, umbilicaric acid (Z. 1898). G. vellea, gyrophoric acid and gyrophorin, melting-point 189° (Z. 1899). G. spodochroa, var. depressa, gyrophoric acid (Z. 1900). G.polyrrhiza, umbilicaric acid, lecanoric acid, gyrophoric acid (Z. 1905).

Hæmatomma ventosum, divaricatic acid, C₂₂H₂₆O₇, melting-point 149° (Z. 1898); -usnic acid, divaricatic acid, and an acid resembling alectoric acid (H. 1900). H. coccineum, var. leiphæmum, leiphaemin, melting-point 193°, atranorin, zeorin (Z. 1902). H. coccineum, var. abortivum, coccic acid, C₁₂H₁₆O₁₀, 3H₂O, melting-point 262-264°, atranorin, haematomin, C₁₀H₁₆O or C₂₀H₃₂O₂, melting-point 143-144°, and haematommidin, melting-point 194-196° (Z. 1903); no zeorin (H. 1907). H. coccineum, var. (?) lecanoric acid, (H. 1907). H. coccineum, var. (?) (from Wildbad), coccic acid, atranorin, zeorin, hydrohaematommin, C₁₀H₁₈O, melting-point 101° (H. 1906). H. coccineum, l-usnic acid, zeorin, atranorin, porphyrillic acid, hymenorhodin, and leiphaemin (Z. 1906). H. leiphæmum, atranorin, zeorin, leiphaemin, leiphaemic acid, C₃₂H₄₆O₅, melting-point 114-115°(Z. 1903). H. porphyrium, atranorin, zeorin, porphyrilic acid, leiphaemin, hymenorhodin (Z. 1906).

Pertusaria dealbata, Nyl. f. corallina, Cromb. (Isidium corallinum) ("white crottle"), calcium oxalate (Braconnot, Ann. Chim. Phys., [ii.], 28, 319).

Lecanora atra, atranoric acid (atranorin), C₁₉H₁₈O₈, and a yellow crystalline substance (Paternò and Oghaloro, Gazz. chim. ital., 1877, 7). Hesse (Ber., 10, 1324) considers the atranoric acid to be hydrocarbonusnic acid, and the yellow substance to be cladonic acid. Obtained from certain districts it contains lecanorol (Z. 1897), C₂₇H₃₀O₉, H₂O. L. varia, psoromic acid and l-usnic acid (Z. 1905). L. grumosa, atranorin and lecanorol (Z. 1897). L. cenisea, atranorin and roccellic acid, C₁₇H₃₂O₄ (cf. Schunck and Hesse, Roccella tinctoria}. L. sordida, atranorin, zeoric acid (Z. 1897). L. sordida, var. glaucoma, atranorin and parellic acid (H. 1898). L. sordida, var. Swartzii, atranorin, thiophanic acid, C₁₂H₆O₁₂.H₂O, melting-point 242°, roccellic acid, lecasteric acid, C₁₀H₂₀O₄, melting-point 116°, and lecasteride, C₁₀H₈O₃, melting-point 105° (H. 1898). L. campestris, atranorin (Z. 1897). L. badia, stereocaulic acid (Z. 1897). L. effusa, atarnorin and usnic acid (Z. 1897). L. subfusca, atranorin (Z. 1897); (H. 1900). L. epunora, zeorin and lepanorin, melting-point 131° 132° (Z. 1900), L. glaucoma (L. sordida a-glaucoma) (from Tyrol), atranorin, thiophanic acid, roccellic acid (Z. 1903). L. sulphurea, usnic acid (Z. 1903). L. parella ("light erottle"), parellic acid, lecanoric acid (Schunck, Annalen, 54, 257, 274; 41, 161). L. tartarea (Linn.) (Patellaria tartarea, Parmelia tartarea), erythric acid, synonymous with Nees. v. Esenbeck's "remarkable resin" (Brandes' Archiv. Apoth., 16, 135), with Heeren's erythrin, and with Kane's erythrilin (Schweiggers, J. Ch. Phys., 59, 313). Schunck found crustaceous lichens belonging to Lecanora, etc., collected on the basalt rocks of the Vogelsberg in Upper Hessia to contain lecanoric and erythric acids (Annalen, 41, 157). In a specimen from Norway, Stenhouse (ibid., 70, 218) found gyrophoric acid. L. ventosa, usnic acid (Knop, ibid. 49, 122).

Rhizocarpon geographicum, Dl. (Lecidea geographical], usnic acid (Knop, loc. tit.). Lecidea Candida (Psora Candida), calcium oxalate (Braconnot, Ann. Chim. Phys., [ii.], 28, 319). L. cineroatra, lecidic acid, C₂₂H₂₇O₄.COOMe, melting-point 147°, and lecidol, melting-point 93° (H. 1898). L. sudetica, salazinic acid (Z. 1899). L. confluens, confluetin, melting-point 147-148° (Z. 1899). L. grisella, gyrophoric acid (H. 1900). L. agloeotera (L. armeniaca, var. lutescens), roccellic and cetraric acids (Z. 1904).

Lepraria latebrarum, leprarin, melting-point 155°, roccellic acid (Z. 1897), and atranorin (Z. 1900); d-usnic, hydroroccellic, lepraric, and talebraic acids (melting-point 208°), and atranorin (H. 1903). L. flava, calycin, pinastric acid, calyciarin (Z. 1905). L. xanthina (from Vorarlberg), physcion (H. 1906). L. latebrarum (Baden- Baden), atranorin, leprariaic acid, oxyroccellic acid, and neobraic acid (H. 1906). L. candelaris, calycin (Z. 1906). L. chlorina, calycin (Z. 1895).

Lepra candelaris (Lepraria flava), calycin, C₁₈H₁₁O₄.OH, melting-point 240-242° (H. 1898).

Leprantha impolita (Arthonia pruinosd), lecanoric acid, lepranthin, C₂₅H₄₀O₁₀, melting-point 183°, lepranthaic acid, C₂₀H₃₂O₂, melting-point 111-112° (Z. 1904).

Mycoblastus sanguinarius, caperatic acid and atranorin (Z. 1899).

Menegazzia pertusa (Parmelia pertusa), atranorin and farinacic acid (capraric and pysodic acids absent) (H. 1907).

Nephroma arcticum, zeorin, nephrin, and d-usnic acid (Z. 1909). N. antarcticum, zeorin and d-usnic acid (Z. 1909). N. parile, zeorin and mannitol (Z. 1909). N. resupinatum, mannitol (Z. 1909). N. lævigatum, mannitol (Z. 1909). Nephromium lævigatum, usnic acid and nephrin, C₂₀H₃₂, H₂O, melting-point 168° (H. 1898). N. tommentosum, usnic acid and nephrin (H. 1898). N. lusitanicum, nephrin and nephromin, C₁₀H₁₂O₆, melting-point 196° (H. 1898).

Ochrolechia androgyna (Lecanora subtartarea), gyrophoric acid and calyciarin (Z. 1905). O. pallescens, var. parella (from Auvergne), parellic acid and ochrolechiasic acid, C₂₂H₁₄O₉, melting-point 282° (H. 1906); but no lecanoric acid (see Schunck, Annalen, 1845, 54, 274) (Z. 1898). O. tartarea, gyrophoric acid (Z. 1898).

Pannaria lanuginosa, hydroxyroccellic acid, C₁₇H₃₂O₅ melting-point 1284°, and pannaric acid, C₉H₈O₄, melting-point 224° (H. 1901).

Parmelia aleurities, atranorin (Z. 1897). P. tiliacea, atranorin and parmelialic acid, melting-point 165° (Z. 1897); the latter is in reality lecanoric acid (H. 1898 and 1900). P. perlata, atranorin and haematommic acid (Z. 1897); usnic acid, lecanoric acid, and perlatin (H. 1900); imbricaric acid (Z. 1902); no lecanoric acid (H. 1903); atranorin and perlatic acid, C₂₇H₂₇O₉.OMe, 2H₂O (H. 1904). P. perlata from certain sources: (a) atranorin, (b) atranorin, usnic, and vulpic acids, (c) atranorin and lecanoric acid, (d) atranorin and perlatin C₁₉H₁₄O₅(OMe)₂ (H. 1898). P. saxatilis, var. sulcata, atranorin and stereocaulic acid (Z. 1897); protocetraric acid only (H. 1900), not protocetraric but pannatic acid (H. 1904); usnic acid (Schmidt, Annalen, 51, 29). P. saxatilis, var. panniformis) atranorin, protocetraric acid, and usnetic acid, C₂₄H₂₆O₈ (not C₉H₁₀O₃), melting-point 192° (H. 1900). P. saxatilis retiruga, atranorin, protocetraric acid, and saxatic acid, C₂₅H₄₀O₈, melting-point 115° (H. 1903). P. physodes (or P. ceratophylla, var. physodes) is known as "dark crottle," and is employed for dyeing a brown colour on homespun woollen yarn. Contains physodin and two colourless substances (Gerding, Brandes, Arch. Pharm., [ii.], 87, i), ceratophyllin (H. Annalen, 119, 365); atranorin, physodalic acid, and physodalin (Z. 1897 and 1898); evernuric acid, physodylic acid, capraric acid, and atranorin (H. 1907). P. parietina, chrysophanic acid (Rochleder and Heldt); identical with Thomson's (Edin. New Phil. Jour., 37, 187) parietin, also (H. 1895) physcion, C₁₆H₁₂O₅, physcianin, c₁₀H₁₂O₄, melting-point 143°, and physciol, C₇H₈O₃, melting-point 107°. A variety of P. parietina growing on sandstone rock and not on trees like that of Rochleder and Heldt, contained vulpic acid (chrysopicrin), (Stein, J. pr. Chem., [i.], 93, 366). P. caperata ("stone crottle"), emulsin (Hérissey, J. Pharm., [vi.], 7, 577); capraric acid, C₂₂H₁₈O₈(COOH)₂, melting-point 240°, usnic acid, caperatic acid, COOMe, C₁₈H₃₃O₂(COOH)₂, melting-point 132°, and caperin, C₃₆H₆₀O₃, melting-point 243 (H. 1898), P. caperata from Castanea vesca, usnic, capraric and caperatic acids (H. 1904). P. conspersa, usnic acid, zeorin, and atranorin (Z. 1898); usnic acid and salazinic acid (H. 1898); d-usnic acid and conspersaic acid, melting-point 252° (H. 1903). P. acetabulum, atranorin (Z. 1898); atranorin and salazinic acid (H. 1901). P. excrescens, zeorin and atranorin (Z. 1898). P. perlata, var. exrescens, atranorin (Z. 1898). P. Nilgherrensis, atranorin (Z. 1898). P. perforata, zeorin and atranorin (Z. 1898); lecanoric acid (H. 1900). P. olivetorum, atranorin (Z. 1898); lecanoric acid, but no erythric acid (H. 1900); olivetoric acid, C₂₇H₃₄O₈, melting-point 141-142° (Z. 1902); atranorin, olivetorin, melting-point 143°, and olivetoric acid, C₂₁H₂₆O₇ (H. 1903). P. pertusa, physodalic acid (Z. 1898). P. fuliginosa, atranorin and lecanoric acid (H. 1898). P. fuliginosa, var. ferruginascens, lecanoric acid (Z. 1899). P. pulverulenta, unknown acid (H. 1898). P. ciliaris, everninic acid and atranorin (?) (H. 1898). P. omphalodes (P. saxattilis, var. omphalodes}. Under the name of "black crottle" this lichen is employed for dyeing a brown colour in the outer Hebrides (Lewis and Harris); contains stereocaulic acid (Z. 1899). P. tiliacea, var. scortea, lecanoric acid (Z. 1899). P. verruculifera, lecanoric acid (Z. 1899). P. glomellifera, glomelliferin, melting-point 143-144° (Z. 1899 and 1902). P. incurva, usnic acid (Z. 1900). P. Borreri, lecanoric acid (Z. 1900). P. sorediata, diffusin (Z. 1900); lecanoric acid (H. 1900). P. tinctorum, atranorin (H. 1900). P. tinctorum (E. Africa), atranorin and lecanoric acid (H. 1906). P. tinctorum (Madras cinchona bark), atranorin and lecanoric acid (H. 1904). P. glabra, lecanoric acid (H. 1902). P. lacarnensis, imbricaric acid (Z. 1902). P. sinuosa, d-usnic and usnaric acids (Z. 1902).

Parmelia cetrata (Java cinchona bark), cetrataic acid, C₂₉H₂₄O₂₅, melting-point 178-180° (H. 1903). P. olivacca, oliveacein, C₁₇H₃₂O₆.H₂O, melting-point 156°, and oliveaceic acid, C₁₆H₁₉O₅.OMe, melting-point 138° (H. 1903). P. revoluta, atranorin and gyrophoric acid (Z. 1905). P. pilosella, atranorin and pilosellic acid, melting-point 245 (Z. 1905). P. Moûgeotti, d-usnic acid (H. 1906).

Peltigera apthosa, peltigerin, C₂₁H₂₀O₈ (or C₁₆H₁₆O₆ ), melting-point 170-180°, and mannitol (Z. 1909). P. malacea, peltigerin, zeorin, and mannitol (Z. 1909). P. horizontalis, peltigerin, zeorin, and mannitol (Z. 1909). P. polydactyla, peltigerin, mannitol, polydactylin, melting-point 178-180°, and peltidactylin, melting-point 237-240°. P. venosa, peltigerin. P. scabrosa, peltigerin. P. propagulifera, peltigerin and zeorin. P. lepidophora, peltigerin. P. praetextata, mannitol. P. rufescens, mannitol. P. spuria, mannitol. P. canina, caninin (Z. 1909); emulsin (Hérissey, J. Pharm. Chim., [vi.], 7, 577).

Pertusaria amara (P. communis β-variolosa, Variolaria amara), emulsin (Hérissey, loc. cit.); cetraric acid, pertusaric acid, C₂₄H₃₈O₆, melting-point 103°, pertusarin, C₃₀H₅₀O₂, melting-point 235°, pertusarene, C₃₀H₁₀₀, melting-point 286°, and pertusaridin (H. 1898); salazinic acid and picrolichenin (Z. 1900); orbiculatic acid, C₂₂H₃₆O₇ (H. 1901). P. lactea, lecanoric acid and variolaric acid, melting-point 285° (Z. 1902). P. lactea (sterile Auvergne), lecanoric acid and ochrolechiasic acid (H. 1906). P. corralina (P. ocellata β-coralline), ocellatic acid, C₂₀H₁₅O₁₁.OMe, melting-point 208° (H. 1901). P. rupestris (P. communis β-areolata) areolatin, C₁₁H₇O₆. OMe, melting-point 270°, areolin, melting-point 243°, and gyrophoric acid, C₁₆H₁₄O₇ (H. 1903). P. glomerata (Wildbad), porin, C₄₂H₆₇O₉OMe, melting-point 166°, and porinic acid 2[C₁₁H₁₂O₄], H₂O, melting-point 218° (H. 1903). P. Wulfenii (P. stilfurea, P. sulphurella, P. fallax), thiophanic acid (Z. 1904). P. lutescens, thiophanic acid (Z. 1904).

Placodium gypsaceum, squamaric acid and usnic acid (Z. 1898); parellic acid, but no usnic acid (H. 1901). P. chrysoleǔucǔm, usnic acid (Z. 1898). P. saxicolum, var. vulgare, usnic acid and zeorin (Paternó, Atti. R. Accad. Lincei, 1876, [ii.], 3); zeorin, but no atranorin (H. 1898), -usnic acid (H. 1900). P. saxicolum, var. compactum, atranorin (H. 1901). P. melanaspis, atranorin (Z. 1898). P. Lagascoe, psoromic and usnic acids (Z. 1897).

Placodium crassum, atranorin (trace), l-usnic acid (H. 1901). P. circinatum (a) radiosum, salazinic acid (H. 1902).

Physcia ciliaris, emulsin (Hérissey, J. Pharm. Chim., [vi.], 7, 577). P. endococdna, zeorin and atranorin (Z. 1895), rhodophyscin and endococcin (Z. 1905). P. caesia, zeorin and atranorin (Z. 1895); atranorin and zeorin (H. 1902). P. stellaris, f. adscendens, atranorin (Z. 1895). P. parietina, atranorin and placodin, melting-point 245° (H. 1899). P. medians, vulpic acid and calycin (Z. 1895), calycin and callopismic acid (Z. 1897). P. pulverulenta, var. β-pityrea, atranorin (Z. 1895).

Physcia tenella, atranorin (Z. 1895). P. aipolia, atranorin (Z. 1895).

Cetraria glauca (Platysma glaucum), atranorin and caperatic acid (Z. 1899). Cetraria cucullata (P. cucullatum), lichenostearic acid and usnic acid (Z. 1899). P. diffusum, diffusin, melting-point 135-136°, and usnic acid (Z. 1899).

Pleopsidium chlorophanum, rhizocarpic acid (Z. 1895).

Pseudevernia ericetorum, atranorin, physodalin (Z. 1905).

Psora ostreata, lecanoric acid (Z. 1899).

Pulveraria chlorina, calycin, vulpic acid, and lepraric acid, melting- point 228° (H. 1898). P. latebrarum, atranorin, parellic acid, latebride, melting-point 128°, and pulverin, melting-point 262° (H. 1898). P. farinosa, oxyroccellic acid, and pulveraric acid, melting-point 234° (H. 1898).

Raphiospora flavovirescens, rhizocarpic acid (Z. 1895).

Ramalina calicaris, var. fastigiata, contains large quantities of starch (lichenin) and a small quantity of saccharic acid (Berzelius, Scherer's Annalen, 3, 97), usnic acid (Rochleder and Heldt, ibid., 48, 9). R. calicaris, var. fraxinea, lichenin and usnic acid (Rochleder and Heldt, loc. cit.); a-usnic acid (Hesse, Annalen, 117, 297). R. ceruchis) usnic acid and usnaric acid (H. 1898). R. armorica, atranorin, armoricaic acid, melting-point 240-260°, armoric acid, C₁₈H₁₈O₇, H₂O, melting-point 226-228° (H. 1907). R. cuspidata, cuspidatic acid, C₁₆H₂₀O₁₀, melting-point 218° (H. 1900). R. farinacea, d-usnic acid and ramalic acid, melting-point 240-245° (H. 1903). R. subfarinacea, d-usnic acid and salazinic acid (Z. 1907). R. minuscula, d-usnic acid (Z. 1907). R. Kullensis, d-usnic acid, kullensisic acid, C₂₂H₁₈O₁₂ (Z. 1907). R. obtusata, d- usnic acid, ramalinellic acid, melting-point 169°, and obtusatic acid (Z. 1907). R. Landroënsis, d-usnic acid and landroënsin (Z. 1907). R. pollinaria, ramalic acid, C₁₈H₁₃O₃OMe, and evernic acid (Z. 1897); usnic acid, atranorin, evernic acid, and ramalic acid (H. 1898). R. fastigiata, emulsin (Hérissey, J. Pharm. Chim., 1898, [vi]. 5, 577). R. fraxinea, emulsin (Hérissey, ibid.}. R. polymorpha, usnic acid (Z. 1897). R. scopulorum (see Thomson, Annalen, 53, 252), d-usnic acid, scopuloric acid, C₁₉H₁₆O₉, melting-point 260° (Z. 1907). R. thrausta, usnic acid (Z. 1900). R. yemensis, d-usnic acid (H. 1902).

Reinkella birellina, roccellic and oxyroccellic acids (H. 1898).

Rhizocarpon geographicum f. contiguum, parellic acid, rhizonic acid, C₁₉H₂₀O₇, melting-point 185°, rhizocarpic acid, C₂₈H₂₂O₇ (H., Ber., 1898, 31, 663), rhizonic acid is OMe.C₁₇H₁₄O₂(OH)2COOH (H.).

R. geographicum f. lecanorinum, rhizocarpic acid (Z. 1895); parellic acid, rhizocarpinic acid, melting-point 156°, rhizocarpic acid, COOH.C₂₄H₁₆O₃.COOEt, melting-point 177-178°. Parellic acid, COOMe.C₁₇H₁₁O₃(COOH)₂, melting-point 262-265°, is the same as Zopfs psoromic acid, and the squamaric acid and zeoric acid of other writers (H.). R. geographicum f. geronticum, parellic and rhizocarpic acids, but not rhizocarpinic acid (H., 1909).

Rhizoplaca opaca (Lecanora chrysoleuca, β-opaca, Parmelia rubina, β-opaca, Squamaria chrysoleuca β-opaca), usnic acid, placiodilic acid (previously termed placiodïlin), rhizoplacic acid, C₂₁H₄₀O₅, melting- point 94-95° (Z. 1905), usnic acid and placiodilic acid, C₁₇H₁₈O₇, melting-point, 156-157° (Z. 1906).

Roccella fuciformis (R. tinctoria, var. fuciformis]. This wellknown "orchella weed" is imported from Angola, Zanzibar, Madagascar, Ceylon, and Lima for the purpose of manufacturing archil and cudbear. It contains erythric acid (Heeren's erythrin, Kane's erythrilin) and roccellic acid (Schunck, Pharm. J., [iii.], 39, 164; Annalen, 61, 64; Kane, Trans. Roy. Soc., 1840, 273; Heeren and Schweiggers, J. Pharm. Chim., 59, 346). Stenhouse (Annalen, 149, 288) examined a Lima weed in 1848, and found it to contain lecanoric acid, but this was probably R. tinctoria and not identical with the R. fuciformis examined by him in 1869, and in which he found erythric acid. Cf. Hesse (Annalen, 117, 329, and 139, 22) who found Lima weed to contain erythric acid, but not lecanoric acid. Stenhouse considers the R. Montagnei from Angola, in which he found erythric acid to be identical with R. tinctoria, var. fuciformis, examined by Schunck. A stunted variety of R. fuciformis, examined by Menschutkin and Lamparter, contained β-erythrin. In a better growing specimen erythrin was obtained (Lamparter, Annalen, 134, 243). A variety of R. fuciformis, probably from the west coast of Africa, contained erythric acid and a bkter substance picroroccellin (Stenhouse and Groves, ibid.) 185, 14). More recently Hesse (1898) has found the weed to contain erythric acid and oxyroccellic acid.

Roccella Montagnei, erythric acid and oxyroccellic acid (H. 1898); orcinol (Ronceray, Bull. Soc. Chim., 1904, [iii.], 1097). R.fruticosa, erythric acid (erythrin) (H., Ber., 1904, 37, 4693). R. phycopsis (Crete), erythrin, oxyroccellic acid, oxalic acid, and erythritol (H. 1906). R. peruensis (R. fructectosa and R. cacticola], erythrin, oxyroccellic and roccellic acids (H. 1898), erythrin, erythritol and oxalic acid (H. 1906). R. portentosa, lecanoric acid (H. 1898). R. decipiens, lecanoric acid (H. 1898). R. sinensis, lecanoric acid (H. 1898).

Roccella tinctoria. - This lichen, used largely for the manufacture of orchil and cudbear, is imported from the Cape of Good Hope, the Cape Verde Islands, and Chile (Valparaiso weed). Formerly it seems to have been imported also from Lima (Stenhouse). It contains lecanoric acid (Stenhouse's α- and β-orsellic acid) and roccellinin. The latter is, however, probably a decomposition product of the former (Stenhouse, Annalen, 68, 55; 149, 288; Phil. Mag., [iii.], 32, 300). According to Hesse (1898) it contains erythrin, oxyroccellic acid, roccellic acid, and lecanoric acid, whereas Ronceray (Bull. Soc. Chim., 1904, [iii.], 31, 1097) detected in this lichen the presence of lecanoric acid and orcinol (cf. Hesse, Ber., 1904, 37, 4693).

Roccellaria intricata, zeorin and roccellaric acid, melting-point 110° (H. 1898).

Squamaria elegans (Gasparrinia elegans) chrysophanic acid (Thomson, Phil. Mag., [iii.], 25, 39); physcion (H.).

Solorina crocea, soloric acid, melting-point 199-201° (Z. 1895).

Spharophorus fragilis, sphaerophorin, melting-point 138-139°, and fragilin (Z. 1898), sphaerophorin (C₁₄H₁₆O₄)_n, or C₂₈H₃₄O₈, sphaerophoric acid, melting-point 206-207°, and fragilin (Z. 1905).

Sphyridium placophyllum, atranorin (Z. 1898).

Stereocaulon alpinum, atranorin, and stereocaulic acid, melting-point 200-201° (Z. 1895). S. coralloides, atranorin and psoromic acid (Z. 1895), usnetic acid, atranorin, and an acid not psoromic acid. Zopfs stereocaulic acid from S. alpinum is usnetic acid (H. 1900). S. incrustatum, atranorin and psoromic acid (Z. 1895). 5. vesuvianum, psoromic acid (Z. 1895). S. denudatum, var. genuinum, atranorin (Z. 1895). 5. tomentosum, atranorin (Z. 1895). S. pileafum, atranorin and stereocaulic acid (Z. 1895 and 1899). S. condensatum, atranorin (Z. 1895). S. paschale, atranorin (Z. 1895). S. virgatum f. primaria, atranorin (Z. 1895). S. ramulosum, atranorin (Z. 1895). S. salazinum, salazinic acid, which blackens at 260-262° (H. 1900).

Sticta fuliginosa, trimethylamine (Z. 1897). S. aurata, stictaurin, a derivative of pulvic acid (Z. 1899). Stictaurin has the formula C₁₈H₁₂O₅ (H. 1900). S. desfontainii, calycin and ethyl-pulvic acid (H. 1900). S. pulmonaria, stictaic acid, C₁₈H₁₁O₈(OMe), melting-point 264°, stictinic acid (Knop and Schnedermann, J. pr. Chem., 1846, 39, 365), and not protocetraric acid (H. 1900). This lichen is known as "hazel crottle".

Stictina gilva, stictinin, melting-point 160-161° (Z. 1905).

Thamnolia vermicularis, thamnolic acid, melting-point 202-204° (Z., Chem. Zentr., 1893, [ii.], 54). According to Hesse this has the formula C₁₉H₁₅O₁₀.OMe (1898 and 1900).

Thallædema candidum, probably lecanoric acid (H. 1898).

Thalloschistes flavicans, parietin (Z. 1905) (Brittany); physcion and acromelin (H. 1907).

Tornabenia chrysophthalma, physcion (H. 1907). T. flavicans, var. crocca, physcion (H. 1907). T. flavicans, var. acromela (Physcia acromela}, acromelin, C₁₇H₂₀O₉ melting-point, 242°, and acromelidin, C₁₇H₂₀O₂, melting-point 162° (H. 1907). T.flavicans, var. cinerascens, physcion and acromelin (H. 1907).

Umbilicaria pustulata (Gyrophora pustulatd), gyrophoric acid, C₁₈H₁₈O₇ (?), (Stenhouse, Annalen, 70, 218; Z. 1898; H. 1898).

Urceolaria lichens, collected from the basalt rock of the Vogelsberg in Upper Hessia, contain lecanoric and erythric acids (Schunck, Mem. Chem. Soc., 1, 71).

Urceolaria scruposa, var. vulgaris, atranorin and lecanoric acid (H. 1898, 1904, 1907); patellaric acid (Z. 1902). U. cretacea (U. scruposa, var. gypsacea), lecanoric acid, but no atranorin, zeorin, or parmelialic acid (H. 1898; cf. Zopf, 1897).

Usnea barbata {Lichen barbatus, Parmelia barbata) usnic acid (Rochleder and Heldt, Annalen, 48, 8; Stenhouse, ibid., 155, 51), and lichenin (Berzelius, Scherer's Annalen, 3, 205; Hesse, Annalen, 137, 241; Ber., 10, 1324), usnic and barbatic acids (H. 1898); emulsin (Hèrissey, J. Pharm. Chim., [vi.], 7, 577). U. barbata f. dasypoga, usnic acid and usnaric acid, C₃₀H₂₂O₁₅, melting-point 240-260° (H. 1898), d-usnic, usnaric, and alectoric acids (H. 1900); barbatic, usnic, and usnaric acids, but no alectoric acid (Z. 1902); alectoric acid (H. 1903). U. barbata, var. ceratina, usnic acid, C₁₈H₁₆O₇, melting-point 195-196°, and barbatin (H., Annalen, 1895, 284, 157). U. barbata α-florida, d-usnic, usnaric, and parellic acids, and usnarin (H. 1902). U. ceratina, usnic acid, barbatic acid and barbatin (H. 1898). U. ceratina (Black Forest), barbatic and usnic acids (Z. 1902), d-usnic acid, barbatic acid, and barbatin (H. 1903), (Java cinchona bark), d-usnic, usnaric, and parellic acids and ceratin (H. 1903). U. ceratina β-hirta (Bolivian), d-usnic, usnaric, p'icatic, and barbatic acids (H. 1903). U. barbata (β) hirta, d-usnic, usnaric, and barbatic acids, and usnarin (H. 1902), atranorin (H. 1906). U. barbata (β) hirta (St. Thomas), d-usnic and usnaric acids, and santhomic acid, C₁₁H₁₄O₄, melting-point 166° (H. 1902). U. hirta, usnic acid (Knop, Annalen, 49, 103), usnic acid, alectoric acid, hirtic acid, melting-point 98°, and hirtellic acid (melting-point 215° decomp.), (Z. 1903). U. cornuta, d-usnic and usnaric acids (Z. 1902). U. longissima, barbatic and usnic acids (Z. 1897; H. 1898). U. longissima (from Amani), ramalic acid, d-usnic acid, and dirhizonic acid, C₁₈H₁₆O₅(OMe)₂, melting-point 189° (H. 1906). U. florida, usnic acid (Knop, Annalen, 49, 103); usnic acid and hirtellic acid (Z. 1904). U. schraderi, d-usnic acid and usnaric acid (Z. 1905). U. microcarpa, d-usnic acid and usnaric acid (Z. 1905). U. articulata, var. intestiniformis (Indian cinchona bark), d-usnic acid, barbatic acid, and articulatic acid, C₁₈H₁₆O₁₀ (?), (H. 1907). U. plicata, d-usnic acid, usnaric acid, usnarin, and plicatic acid, C₂₀H₃₃O₈(OMe), melting-point 133° (H. 1900). U. scrŭposa, atranorin and lecanoric acid (Z. 1902).

Pertusaria dealbata, Nyl. (Variolaria dealbata, Lichen dealbatus), variolarin (Robiquet, Annalen, 42, 236; 58, 320). Schunck found crustaceous Variolaria collected on the basalt rocks of the Vogelsberg in Upper Hessia, to contain lecanoric and erythric acids.

Xanthoria parietina (Parmelia parietina, Physria parietina), atranorin and physcion (H. 1898). X. lychnea, physcion (H. 1898). X. candelaria (X. controversa, X. lychnea, var. pygmxa X. parietina, var. lychnea), parietin, melting-point 202° (Z. 1904).