PEROXIDE OF HYDROGEN.--A Nvatery solution of hydrogen dioxide. It is a colourless liquid, with a slightly acid taste. When applied to a mucous membrane, it produces a peculiar froth, which is due to coagulation of albumin. It is used as a deodorant and as an antiseptic, especially in inflammations of mucous membranes. The use of peroxide for bleaching dark hair is well known.
PERSPIRATION.—The excretion of fluid by the sweat glands of the skin (see p. 112). Under ordinary conditions the amount of sweat, excreted, although quite considerable, does not form visible drops, since it evaporates as rapidly as it forms. In very warm weather, however, the quantity becomes greatly increased, and accumulates in beads on the surface of the skin. The feet and the armpits are plentifully supplied with sweat glands, and excessive perspiration in these parts is very common. The sweat serves as a means of regulating the body-heat, and also to carry off certain waste-products of metabolism.
In certain diseases, principally of the kidneys, the amount of sweat excreted may be considerably lessened ; while other diseases, such as various febrile affections, cause increased perspiration. When sweat is allowed to accumulate on any part of the body, it will decompose and give rise to a very offensive odour. This is especially noticeable in perspiring feet. Of fensive perspiration may occur also in certain diseases, notably in rheumatic affections. In some catarrhal and febrile affections, it is often desirable to increase perspiration, and certain remedies (sudorifics) are employed for this purpose. See DOMESTIC REMEDIES ; MEDICINES. With regard to the treatment of excessive or ill-smelling perspiration, cleanliness is the all important remedy. See SKIN, CARE OF.