The coal-tar colors : with especial reference to their injurious qualities and the restriction of their use / a sanitary and medico-legal investigation, by Theodore Weyl, with a preface by Professor Sell, tr. with permission of the author by Henry Leffman.

  • Weyl, Theodor, 1851-1913.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: The coal-tar colors : with especial reference to their injurious qualities and the restriction of their use / a sanitary and medico-legal investigation, by Theodore Weyl, with a preface by Professor Sell, tr. with permission of the author by Henry Leffman. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    they were named according to source, as aniline, phenol, and naphthol colors. Subsequent research has elucidated the atomic structure, and rendered possible a classification in natural groups based on the chemical constitution. The following are some of the most important groups, with examples of each: I. Nitroso-colors. Naphthol green B, solid green. II. Nitro-colors. Picric acid, Martins' yellow, naphthol yellow S, aurantia. III. Azo-colors. Aniline yellow, Bismarck brown, Biebrich scarlet, fast yellow, fast red, tropaeolin. IV. Triphenylmethane colors (anilines, properly so called), fuchsin, malachite green, Victoria green. V. Rosolic acid colors. Corallin, rosolic acid. VI. Phthalein colors. Eosin, erythrosin. VII. Anthracene colors. Alizarin, alizarin orange. VIII. Indigo colors. Indigo. IX. Quinoline colors. Quinoline yellow, cyanine, chrys- aniline. X. Indophenol colors. Methylene blue. XI. Azine colors. Safranin, magdala red. XII. Aniline black. The characteristics of these groups will be given in the Special Part. These dyes deport themselves in part as acids (acid dyes), partly as bases (basic dyes), and in part as indifferent bodies (neutral dyes). Indigo belongs to the last group. Among the acid colors are the nitrated and sulphonated bodies, such as pic- ric acid, oranges, ponceaux, and all nitro-colors. Basic colors are salt-like combinations of color bases with acids, e. g., fuchsin and methylene blue, and are precipitated by tannin or picric acid in the presence of sodium acetate. Acid colors are mostly in- soluble in water, but dissolve in alkalies. Nomenclature.—The trade names of the coal-tar colors are mostly fanciful, since the scientific titles are cumbersome and difficult to remember. Thus, tetramethylthionine hydrochloride is called methylene blue; aurantia is hexanitrodiphenylamine ; wool-black is the sodium salt of sulphazosulphobenzeneparazo-