(1) A portion was gently warmed with a few drops of a strong solution of potassium cyanide and two drops of sodium hydroxide. The red color of potassium isopurpurate was formed.
(2) A portion of the water solution was heated with glucose and a few drops of sodium hydroxide. The deep red color of picraminic acid was produced.
(3) A few drops of an ammoniacal solution of copper sulphate was added to the water extract. A yellow-green precipitate was formed.
(4) The water extract dyed silk, but did not dye cotton cloth.
DISTILLATION OF THE TAR WITH SODA LIME.
About 25 gm. of the tar left after extracting the original material with hot water was dissolved in ether and poured into a glass retort containing soda lime. The ether was distilled out, leaving the tar intimately mixed with the soda lime. The retort was then gradually heated. Vapors and liquid were given off, both of which turned red litmus blue and had a strong odor like tobacco smoke. No odor of ammonia was detected.[45] At the high temperature of the triple burner, a semi-solid, red, greasy substance collected in and closed the condenser tube. This substance had the same powerful odor as the liquid portion of the distillate. The clear, watery portion of the distillate was separated from the thicker parts, and was found to contain pyrrol and pyridine derivatives by the following characteristic tests:
(1) Wood moistened with hydrochloric acid was turned red by it.
(2) Colorless fumes were formed when brought near hydrochloric acid; mixed with hydrochloric acid, a red insoluble substance was formed.
(3) It precipitated the hydroxides of iron, gave a light blue precipitate with copper sulphate, and a white precipitate with mercuric chloride.
The greasy, semi-solid mass was extracted with 10 per cent. hydrochloric acid and filtered. On addition of a solution of mercuric chloride to the red filtrate, a brown flocculent precipitate was formed. It was filtered off and distilled with caustic soda, but the distillate did not contain pyridine.