3. Sulphuretted Hydrogen or Ammonium Sulphide, a milky-white precipitate in a neutral pure solution.
4. Nitrate of Baryta, a white precipitate showing the presence of sulphuric acid.
5. Caustic potash or soda, a white precipitate soluble in excess.
In Organic Mixtures pass sulphuretted hydrogen, collect the sulphuret, and decompose it with boiling hydrochloric acid, then test for zinc.
Treatment.—Tea, coffee, milk, warm water, albumen, and in some cases enemata of gruel and other emollients.
IRON
The preparations of iron which are of importance are the sulphate and the muriate.
Sulphate of Iron
Copperas or Green Vitriol—has been administered as a poison, but more frequently to procure abortion. An ounce has been taken with no other serious effect than the production of violent pain, purging, and vomiting. Constant application of this substance to the body has produced vomiting, pains in the belly and limbs. These symptoms disappear on treatment.
Chemical Analysis.—(1) Hydrosulphuret of ammonia gives a black precipitate. (2) Ferrocyanide of potassium added to it, in solution, gives rise to a greenish-blue precipitate, becoming dark blue on exposure. (3) Chloride of barium will point to the nature of the acid present.