with the important charge of removing from the system about twenty ounces of waste matter every twenty-four hours."—"Insensible perspiration removes from the skin, without trouble and without consciousness, a large quantity of useless materials; and, at the same time, keeps the skin soft and moist, and thereby fits it for the performance of its functions as the organ of external sense."—"Where the perspiration is brought to the surface of the skin, and confined there, either by injudicious clothing, or by want of cleanliness, there is much reason to suppose that its residual parts are again absorbed, and act on the system as a poison of greater or less power, according to its quantity and degree of concentration, thereby producing fever, inflammation, and even death itself." Mr. Combe proceeds to adduce many facts to support the theory that diseases are taken in through the skin, and therefrom infers the necessity of guarding it. "Brocchi ascribes the immunity (from the effects of malaria) of the sheep and cattle which pasture night and day in the Campagna to the protection afforded them "by their wool."—"Similar means have been found effectual in preserving the health of labourer digging and excavating drains and canals in marshy grounds, where, previous to the employment of these precautions; the mortality from fever was very considerable."
"The insensible perspiration being composed of a large quantity of water, which passes off in the form of vapour, and is not seen; and of various salts and animal matter, a portion of which remains adherent to the skin, the removal of this residue by
