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Skin is the outside covering of animal bodies. It has secetal functions[:] protection of the body, secretion of certain body waste products and partial regulation of body temperature. The interest of the biological chemist, the medical practitioner and the dermatologist in skin is thus apparent. Certain animal skins are used in the manufacture of many articles necessary to man[:] shoes, belting, upholstery, bags, etc. Skin, therefore, is of interest to the leather scientist, the tanner and the public.

Despite the apparent importance of skin, little is definitely known of its chemical composition. Gies and his collaborators studied the composition of tendons and ligaments. Tanning literature contains numerous general statements (largely of a theoretical nature) but the only quantitative skin composition figures we have found are those of Rosenthal. After summarizing the bio-chemical literature of related compounds, Rosenthal proceeded to show the protein and ash composition of such skins as dog, calf and goat....

Unless otherwise stated, the following experiments deal mainly with pure corium [the middle layer or "true skin"], obtained by shaving hair, epidermis and fatty layer from the fresh skin. The corium, as we have prepared it, represents about 80 per cent of the cross section area of the skin. Study of the other skin layers is now under way.

All skins examined were of short hair.