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.