Abstract
Summary Specimens of dead skin from various sites of the body were studied to determine the rate of passive diffusion of water under certain environmental atmospheric states. Effects of dry heat, relative humidity, radiant heat, ultraviolet irradiation, air currents and protection of skin by lipid coverings were observed. These factors influence the rate of water loss by diffusion through the skin in a predictable manner. The importance of these observations in relation to acclimatization to a tropical and subtropical environment was discussed. Since the inhibition of the transfer of water through human skin resides in the epidermis, the effects of chemical alteration of constituents of epidermis were also observed. The superficial layer of cells of the epidermis apparently inhibits water diffusion through skin by virtue of diffuse lipid or fat phase supported in a keratin-rich framework. This inhibiting material was not identified or studied in detail.