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.

  • Theodor Weyl
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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    potassium cyanide. Copper picrate is insoluble in alcohol. Ammonium picrate produces with sodium hydroxide no precipi- tate (distinction from brilliant yellow). Picric acid, by reduc- tion with alcoholic solution of ammonium sulphide, forms a red solution of picramic acid (dinitroamidophenol). Hydro- chloric acid solution of stannous chloride produces triamidophe- nol, which,by addition of small amount of ferric chloride, becomes diimidoamidophenol (distinction from all remaining nitro- colors). Ferric chloride produces with picric acid a reddish yellow precipitate, rather easily soluble in water. To detect the acid in textiles and foods, it must be extracted. This is best accomplished by producing an ethereal solution and shaking it with a little alkali. The alkaline picrate can then be tested for by reactions numbers two, four, and seven just mentioned. Applicafio7is.—Picric acid was formerly largely used, either alone or in association with other colors, for dyeing silk, wool and artificial flowers, yellow. It has also been employed in foods, and has had some applications in medicine. In Germany its employment for coloring food is forbidden by the Imperial enactment of 1S88, on account of its poisonous character. The poisonous qualities of picric acid have been much exaggerated. Erb gave a rabbit weighing 1700 grams, .06 gram of potassium picrate daily for ninety days. Slight loss of weight and, occa- sional diarrhoea were noted, but nothing more serious. A rabbit weighing 2065 grams died at the end of nineteen days, after having taken 2.52 grams of the substance. A very young dog received daily, from April 21st to 26th, .24 gram of sodium picrate. From April 28th to May 9th, .36 gram daily of the same, and, therefore, received in the course of about two weeks 5.76 grams of sodium picrate without the appearance of any serious phenomena. May 13th, the same animal received in one dose 1.2 grams of sodium picrate. On the following day it was quite weak, marked diarrhoea and dyspnoea appearing. May 14th, .6 gram were administered, which caused vomiting. About evening .36 gram were administered. May 15th, animal lively ; .24 gram was again given, and in the evening of the same day, .72 gram. ]May i6th, marked weakness was manifested, and .16 gram of the salt was ad-
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