Peroxide of hydrogen is obtained by rubbing up peroxide of barium with distilled water, so as to form a liquid paste, which is added gradually, with constant stirring, to distilled water acidulated with one-third of its weight of hydrochloric acid, contained in a vessel immersed in a freezing mixture. When the muriatic acid is saturated, a fresh quantity of the acid in a concentrated state is added, and then more of the peroxide of barium, and the operation repeated till the solution will hold no more chloride of barium, which is deposited by a mixture of ice and salt, except a small portion which is gotten rid of by adding sulphate of silver to precipitate the sulphate of baryta and chloride of silver. The filtered liquid is then concentrated by sulphuric acid, and the water rising in vapor is absorbed and protoxide of hydrogen is obtained nearly pure, in the form of a colorless liquid of a fluid consistence.

L. Crismer explains a new and economic process for preparing hydrogen peroxide. It depends upon the long-known property of sulphuric ether of taking up and dissolving large quantities of H2O2. Commercial barium oxide, containing from 85 to 90 per cent. of BaO2 is treated with an excess of hydrochloric acid (1.10 specific gravity), and the solution shaken up with an equal volume of ether. The mixture is let stand until separation has taken place, when the ether is drawn off and agitated with distilled water, which latter removes and takes up all the hydrogen peroxide which the ether held in solution. The cleaned ether is separated from the water, and is again shaken with the solution of barium oxide, and again extracted with the distilled water. The operation is repeated five or six times, by which the extraction of H2O2 is complete. The aqueous solution will then form 8 to 9 per cent. of the peroxide, and is entirely neutral and free from solid matter.

Medical Properties And Physiological Action

Peroxide of hydrogen "is a powerful and oxidizing agent on account of its unstable nature, as it immediately reacts with and destroys sulphurated hydrogen, and many other compounds susceptible of change. It possesses the advantage, sometimes a very important one, that the product of its composition (water) is neutral and destitute of chemical activity, while hydrogen peroxide itself has not the extreme tendency to act on inert organic matter which so much diminishes the practical value of the permanganates. On the other hand, hydrogen peroxide possesses true disinfectant properties of a marked character." Fibrin and cellular tissue cause it to evolve oxygen, while albumen, gelatin, urea, and cutaneous tissue have no effect upon it.

Topically, it acts by imparting oxygen to the diseased tissues, and thus destroying them. Bert and Reynard found that soluble ferments do not seem to be affected by it; saliva, diastase, the gastric and pancreatic fluids, continue to act in solutions containing peroxide of hydrogen. The conclusions, therefore, that these, as well as Peau and Baldy, have arrived at are that peroxide of hydrogen, even when very dilute, arrests fermentation due to the development of living organisms, and the putrefaction of all substances which do not decompose it; that containing, according to circumstances, from two to six times its volume of oxygen, it is capable of advantageously replacing alcohol and carbolic acid; that it can be employed externally for dressing wounds and ulcerations of all natures, in injections and in vaporizations, and internally; that the results obtained in the case of the largest operations, up to the present, are in the highest degree satisfactory; that not only fresh wounds, but old ones, proceed rapidly to cicatrization, and reunion by first intention appears to be encouraged by its use as a dressing; that the general as well as the local state appears to be favorably influenced; that the advantage over carbolized water are its not having any poisonous effect nor unpleasant odor, while its application is entirely painless. It is an effective application in a large class of diseases in which mucous membrane tissue is chiefly affected, and for cleansing purposes is considered to be unequaled. Dr. Prince remarks that a drop of pus will decompose peroxide of hydrogen and liberate nascent oxygen, which adheres to and attacks all the adjacent tissues for which it has an affinity, and it thus becomes a powerful bacterial destroyer. Peroxide of hydrogen for surgical use must be entirely neutral, as that obtained generally often contains sulphuric acid, so that its use would not be without danger.

Therapeutic Uses

Peroxide of hydrogen is employed as an internal remedy in low forms of fevers, chronic and subacute rheumatism, whooping-cough, chronic bronchitis, dyspepsia, as it improves digestion, diabetes, etc., etc. Locally employed, it is an effective antiseptic, disinfectant, and a powerful deodorant owing to its oxidizing properties, destroying very rapidly hydrogen, sulphur and similar gases. When it is brought in contact with pus, a rapid change takes place, with evolution of oxygen gas, the pus-corpuscles becoming granular, losing form, and breaking up into detrius. It thoroughly cleanses putrid cavities and abscesses. Owing to its rapid action, however, it cannot take the place of bichloride of mercury, nor has it the germicidal power of this latter agent, although it possesses such properties. As a bactericidal agent, it is very serviceable in mi-crobic affections of the mouth and throat, such as diphtheritic and aphthous stomatitis. It produces little or no irritation when used about tender organs, and can be successfully applied in an unirritating form, so that it comes in contact with and destroys diseased germs ; hence its applicability to dental uses, and in ocular and oral therapeutics, as in gonorrhaeal ophthalmia and mastoid abscess, for example. Peroxide of hydrogen acts very promptly and beneficially in feeble, flabby or ill-conditioned ulcers, chancre, and diphtheritic sores, ozaena, wounds, both fresh and putrid, etc., etc. Peroxide of hydrogen appears to have no injurious effect upon animal cells, but has a very energetic destructive action upon vegetable cells - microbes. It has no toxic properties, and is also harmless when given by the mouth. It is especially applicable in the treatment of diseases caused by germs if the microbian element is directly accessible, and is particularly useful in the treatment of infectious diseases of the mouth and throat.