human
It thus acts as bleach, as neutralizing agent, and as precipitant, and the precipitate itself is a strong adsorbent. On account of its freedom from bases, and because its residue is simply water, peroxide of hydrogen has been found of great service in practice, and in most factories it has shown itself superior not only to the other peroxides, but also to all other oxidizing agents. Its application is simple, a concentrated solution being added to the gelatine sol before or after evaporation. It is the most
gpt
of all the oxidizing agents used in bleaching, and it yields the purest product. Its bleaching action is perfectly satisfactory, but only in a non-acid sol. Hydrogen peroxide is moderately stable in acid solution, and its bleaching action is best in slightly alkaline solution. An acid sol bleaches too slowly, or not at all; an alkaline sol induces evolution of oxygen and consequent waste. The great disadvantage of peroxide of hydrogen is its great expense, which is enhanced by an increasing demand for it in other industries. A minor disadvantage is its instability, which leads to loss in transit and storage. It is sold usually in strengths indicated by the volume of oxygen obtained from unit volume of the solution, when treated with permanganate in a nitrometer (_e.g._