STRUCTURE AND GROWTH OF SKIN.
Similarity of Mammalian skins — Development of skin — Structure of calf-skin — The epidermis — The structure of hair — The sebaceous glands — The development of hair — The hair-sheath — The hair-muscle — The hyaline layer — The corium — Connective tissue — Fat cells — Striped muscle — Elastic fibres — The unhairing process — The sweating process PAGE [46]
CHAPTER VIII.
THE CHEMICAL CONSTITUENTS OF SKIN.
The keratin tissues — Production of gelatine from connective tissue — Analyses of hide and gelatine — Constitution of gelatine — Analysis and Reactions of gelatine — Decomposition of gelatine — Reactions of gelatine — Chondrin — Coriin — Hide-albumin — “Acid” and “alkali” albumins — Egg-albumin — Vitellin — Casein — Keratins — Elastic fibres — Analytical methods — Kjeldahl process PAGE [56]
CHAPTER IX.
THE PHYSICAL CHEMISTRY OF THE HIDE-FIBRE.
Causes of swelling and contraction — The essentials of the tanning process — The constitution of matter — The nature of molecules — Vapour-pressure — Surface-tension — Solution-pressures — Jellies — Crystals — Osmotic pressure — Electrolytic dissociation — Electrolysis — Reactions of ions — Absorption of water by gelatine — Dehydration by alcohol — Action of acids, alkalies and salts on gelatinous fibre — Physical explanation of swelling — Action of acids on gelatine — Action of alkalies on gelatine — Effect of salt — The pickling process PAGE [73]
CHAPTER X.
WATER AS USED IN THE TANNERY.