Food Adulteration And Its Detection PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1887 edition. Excerpt: ...matters in wine. Among those suggested are the following: --1. A few drops of the sample are placed in succession on the smooth surface of a piece of white calcined lime, and notice taken of the tint produced. The following colours are stated to occur with pure and artificially coloured wine: --yellowish brown. rose colour. J? reddish violet. yellowish brown. yellowish red. 2. If ammonium hydroxide be added to the suspected sample to distinct alkaline reaction, then a little ammonium sulphide and the liquid filtered, the filtrate from genuine wine will possess a green tint, whereas that obtained from artificially coloured wine will exhibit other colours, such as red, blue, violet, or brown. 3. 100 c.c. of the wine are evaporated to about onehalf of the original volume, ammonium hydroxide added to alkaline reaction, and the liquid thoroughly shaken. Ether is then added, and the mixture again well shaken. It is next introduced into a separator, and allowed to stand at rest until the ether has risen to the surface, when the lower stratum is drawn off, and the residual ether washed by agitation with water, which is subsequently removed. The ethereal solution is now transferred to a flask connected with a Liebig's condenser, a piece of white %voollen yarn introduced into the liquid, and the contents of the flask distilled at a gentle heat: in presence of the smallest amount of fuchsine, the wool will acquire a very perceptible reddish hue. 4 A slight excess of ammonium hydroxide is added to 50 c.c. of the wine, a piece of white woollen fabric introduced, and the liquid boiled until the alcohol and ammonia are expelled. By this treatment it will be found that most aniline colouring matters, if present, become attached to the wool. Their...