Salt in water, effect of, 86 Salts for tanning, 218-22 Sampling tannins, 116 Sangue del drago, 34 Schmack, 40-50 Screwing objective down on cover, 11 Seal skins, 261 Sebaceous glands, 6 Section of hide, 2 Sections of hide, cutting, 12-15 Shafting in tannery, 236 Shagreen, 258 Shaving dressing leather, 187 Sheep skins, 262 Shumac, 40-50 Site for tannery, 231 Skins, trade in, 255-70 Soaking hides, 133-6 Sod oil, 211 Sodium sulphide, estimating sulphur in, 104 Softening hides, 138 Sole-leather, 132-83 ---- ----, preparing hides, 132-8 ---- ----, tanning materials, 157-68 ---- ----, treatment in the shed, 179-83 ---- ----, treatment in the tan-house, 169-78 ---- ----, unhairing hides, 139-56 Soluble matters in leather, estimating, 106 Splitting dressing leather, 188 Staining hide-sections, 14 Standard solutions, 90 ---- ----, preparing, 95-7 ---- ----, table of, 97 Statistics, 255-71 Steam pipes, 250 ---- power in tannery, 236 ---- trap, 251 Stieleiche bark, 38 Stocking hides, 136 Stretching dressing leather, 191 Striking butts, 179 Structure, anatomical, of hide, 2-16 Stuffing strap-butts, 200 Sudoriferous glands, 6 Sulphides for unhairing, 147-50 Sulphur, estimating, in sodium sulphide, 104 Sulphuric acid, examining, 101 Sumach, 40-50 ----, commerce, 271 ---- extract, 50 ---- mill, 49 ---- plantations, 40-8 Suspender liquors, 172 ---- pits, 169 Sweat glands, 6 Sweating hides, 145-7 Sweet-fern tannin, 54