(Non-official.)

Origin. - It is obtained by the destructive distillation of bituminous rock found near Seefeld in the Tyrolese Alps, which contains enormous quantities of semifossihzed fishes and marine animals.

Description and Properties. - It occurs in the form of a brownish-yellow, transparent, oily liquid, containing about 10 per cent. of sulphur.

Upon being treated with concentrated sulphuric acid ichthyol is converted into ichthyol-sulphonic acid, which readily combines with ammonia and other alkalies, as well as with lithium, zinc, mercury, etc., forming the ammonium ichthyol, sodium ichthyol, zinc ichthyol, etc.

Ammonium ichthyol occurs as a clear reddish-brown, syrupy liquid with a bituminous odor and taste. Soluble in water and in a mixture of equal volumes of ether and alcohol.

Dose. - 2-10 minims (0.12-0.6 Cc).

The other salts of ichthyol-sulphonic acid occur as brownish or black tar-like masses, the sodium salt being the most important, as it is the one most employed when ichthyol is desirable in pill form.

Dose. - Sodium ichthyol, 2-4 grains (0.1-0.25 Gm.).