Distinction of antiseptics and disinfectants -- Lime -- Sulphur dioxide -- Manufacture of sulphuric acid -- Bisulphites and metabisulphites -- Boric acid and borates -- Mercuric chloride -- Mercuric iodide -- Copper sulphate -- Zinc salts -- Arsenic -- Fluorides -- Phenol -- Use of carbolic acid -- Eudermin -- Creasote -- Creolin -- Salicylic acid -- Benzoic acid -- Cresotinic acid -- Anticalcium -- “C.T.” bate -- Naphthalene sulphonic acid -- Naphthols -- Hydronaphthol -- Oxynaphthoic acid -- Carbon disulphide -- Formaldehyde -- Triformol -- Camphor and essential oils PAGE 21 CHAPTER VI. _THE ORIGIN AND CURING OF HIDES AND SKINS._ Marking of hides -- Fellmongering of sheep-skins -- The use of salt -- Salting of packer hides -- Brining -- Dry-salting -- Indian plaster cures -- Analysis of salt-earths -- Salt- and iron-stains -- Drying of hides and skins -- Damage by insects -- The warble-fly -- Damage by branding -- Cockle PAGE 33 CHAPTER VII. _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._