Preparation

By acting on barium peroxide with hydrochloric acid.

Characters

This compound of hydrogen is a liquid of the consistence of syrup, of strong, disagreeable, metallic taste, very unstable, and readily parting with its oxygen; hence, it is a powerful oxidizer. It blanches a solution of litmus. A solution, of sp. gr. 1,006, is in common use abroad for bleaching purposes, and is said to be permanent.

Physiological Action (External)

This liquid, applied locally, whitens the skin and mucous membranes, and acts as a moderate caustic. It has also marked antiseptic power, though not equal to carbolic acid in that respect. Urine mixed with one-tenth of peroxide remained nine months without putrefying (Guttmann). The patent disinfectant termed "Sanitas" is said to depend for its efficacy mainly upon this peroxide.

Physiological Action (Internal)

It produces, when given internally, some oxidizing, stimulating, and, in full doses, irritant effects. The bleaching solution, of sp. gr. 1,006, has been used by Assmuth, Schmidt, and Guttmann for hypodermic injection in animals, and found to cause dyspnoea, clonic convulsions, and death in a few minutes from asphyxia. The last-named observer traces this to the development of bubbles of gas in the right cavities of the heart, the blood frothing up as if air entered by the veins. The result is partially antagonized by injection of ferrous sulphate, implying the combination of this with part of the oxygen liberated (Abstract, Medical Times, ii., 1878).

Therapeutical Action (External)