Coloriasto on väriaiheisten tekstien (ja kuvien) verkkoarkisto
(Archive for colour themed articles and images)
INDEX: coloriasto.net
17.5.11
A Dictionary of Arts: Saffron
A Dictionary of Arts, Manufactures, and Mines; containing A Clear Exposition of Their Principles and Practice
by Andrew Ure, M. D.;
F. R. S. M. G. S. Lond.: M. Acad. M. S. Philad.; S. PH. DOC. N. GERM. Ranow.; Mulh. Etc. Etc.
Illustrated with nearly fifteen hundred engravings on wood
Eleventh American, From The Last London Edition.
To which is appended, a Supplement of Recent Improvements to The Present Time.
New York: D Appleton & company, 200 Broadway. Philadelphia: George S. Appleton, 148 Chestnut St.
MDCCCXLVII
1847
SAFFRON (Saffran, Fr. and Germ.) is a filamentous cake, composed of the stigmata of the flowers of the Crocus sativus. It contains a yellow matter called polychroite, because a small quantity of it is capable of colouring a great body of water. This is obtained by evaporating the watery infusion of saffron to the consistence of an extract, digesting the extract with alcohol and concentrating the alcoholic solution. The polychroite remains in the form of a brilliant mass, of a reddish-yellow color, transparent, and of the consistence of honey. It has the agreeable smell, with the bitter pungent taste, of saffron. It is very soluble in water; and if it be stove-dried, it deliquesces speedily in the air. According to M. Henry père, polychroite consists of eighty parts of colouring matter, combined with 20 parts of a volatile oil, which cannot be separated by distillation till the colouring matter has been combined with alkali. By mixing one part of shred saffron with eight parts of saturated brine, and one half part of caustic ley, and distilling the mixture, the oil comes over into the receiver, and leaves the colouring matter in the retort, which may be precipitated from the alkaline solution by an acid. The pure colouring matter, when dried, is of a scarlet hue, and then readily dissolved in alcohol, as also in the fat and volatile oils, but sparingly in water. Light blanches the reddish-yellow of saffron, even when it is contained in a full vial well corked. Polychroite, when combined with fat oil, and subjected to dry distillation, affords ammonia, which shows that azote is one of its constituents. Sulphuric acid colours the solution of polychroite indigo blue, with a lilac cast; nitric acid turns it green, of various shades, according to the state of dilution. Protochloride (muriate) of tin produces a reddish precipitate.
Saffron is employed as a seasoning in French cookery. It is also used to tinge confectionary articles, liqueurs, and varnishes; but rarely as a pigment.
Ei kommentteja:
Lähetä kommentti