Acid Hyperosmic. A Pungent, Poisonous Acid, From Osmium.

Characteristics. Transparent yellow needles, becoming soft on being warmed, and giving off a highly irritating vapour even at the ordinary temperature.

Therapeutics. A hypodermic solution (5 to 10 drops of a 1 % solution of the crystals) daily, has been employed by Prof. Billroth, of Vienna, in sciatic neuralgia, injected into the subcutaneous tissue. Alternate with it, an injection of Morphia hydrochlor, 1/4 grain, Atropia 1/150 grain.

Potassium osmate, K2 Os 04 2H2 0. In purple crystals, soluble in water, in pills of 1/50 grain each, in epilepsy.

Osmic Acid is reported not to do harm, although it would strongly irritate and darken the outer cuticle. The solution must be protected from the light, as it darkens by age. Formerly used only for microscopic work, to blacken fatty tissue.