Chapter XX: Conclusion

“What is a man,
If his chief good and market of his time,
Be but to sleep and feed? A beast--no more.
Sure, He that made us with such large discourse,
Looking before, and after, gave us not
That capability and godlike reason
To fust in us unused.”

Professor Procter, in his paper, entitled “Problems of the Leather Industry,”[185] says: “There is, however, no reason that all the necessary effects both of puering and bating should not ultimately be attained by purely chemical treatment without the risk and uncertainty which must always attach to bacterial and ferment action.”

[185] J.S.C.I. 1910, p. 331.

While I agree with him in this, still it is well to remember that in the case of one of the very oldest of the fermentation industries, that of the production of alcohol, a comparatively simple body, the natural process has not yet been replaced by a chemical one, and I believe this applies also to the manufacture of vinegar.

Chemical methods of bating may be used for leathers like chrome and alum leather, but even here natural processes like drenching, in which acids are produced gradually during the working of the skins, give more beautiful results. With vegetable tanning materials, the advantage is still on the side of the natural processes when these are conducted in a proper manner.

Finally, the author regrets that the subject of the work is not an inspiring and lofty one, such as is astronomy for example.[186] Limited in extent, imperfect in execution, and in parts only suggestive in character, this little book may perhaps serve as a foundation, on which students of the science of tanning may raise the superstructure of their own experience and eventually perfect the processes touched upon, so that the use of such filthy materials may be entirely avoided. In that case the author’s intention will be fulfilled.

[186] Celestial Objects, Webb, 1881.

FINIS

INDEX.

Absorption phenomena, 70

Abt, Dr. G., 51, 72

Acid “turning” of drench, 237

Acids, action of, 156

---- fractionating, 270

---- deliming with, 9

---- in drench, 265

---- to remove lime, cost of, 11

Adulteration in dog-dung, detecting, 144

Agglutinin, 144

Alum, a term for puer, 3

“Alumed” calf skins, 3

Amend’s bate, 193

Amido compounds, 156

Amines, 163, 206

---- in dung, 154

Ammonia in puer liquors, 41

Ammonium phosphate, 45

Analyses, bird excreta, 53

---- dog dung, 26, 150, 152

---- drench, 249

---- gas, 247

---- grains, 7

---- guano, 150

---- hen dung, 150

---- puer, 26

---- ultimate, of dung, 153

Andreasch, F., 244

Anti-bodies, 143

Anti-calcium, 236

Arginase, 133

Artificial drench, 263

Ash of skin, 39

Authors, list of, 290

_Bacillus butyricus_, 112

---- _c_, 172

---- _Coli commune_, 94

---- _d_, 106, 173, 174

---- _e_, 107, 173

---- _erodiens_, 97

---- from pigeon dung bate, 172

Bacteria, action of, 160

---- bate, examination of, 87

---- bran, pure culture of, 269

---- dung, 89, 98, 102, 161

---- growth in various media, 105

---- pigeon dung, 103

---- putrefactive, 125

---- “Sweating,” 105, 213

Bacterial diastase, 131

_Bacterium furfuris_, 241, 264, 269

---- _termo_, 118

Barium salts from pure cultures of _B. furfuris_, 271

---- ---- of volatile acids, 253

Bate, Amend’s, 193

---- Becker’s patent, 227

---- bird dung, 52

---- Boehringer’s patent, 197

---- concentration of salts in, 47

---- Dermiforma, 189

---- Eberle’s patent, 221

---- Erodin, 179

---- Esco, 192

---- examination of bacteria in, 87

---- glucose, 179

---- Lederer’s, 196

---- Nordlinger’s, 195

---- Norris’s, 194

Bate, Nowak’s patent, 194

---- Oake’s, 195

---- Oropon, 140, 186, 219

---- phosphates in, 43

---- pigeon dung, 103

---- Phosphorbutyralin, 195

---- Popp and Becker’s patent, 197

---- Puerine, 190

---- Purgatol, 192

---- reducing action of, 152

---- Röhm’s patent, 219

---- Simon’s, 195

---- solid matter, influence of, 176

---- soluble matter of, 176

---- Sucanine, 191

---- Tiffany’s, 179

---- Wood’s American patent, 210

---- ---- English patent, 205

---- Zollikoffer’s, 178

Bayliss, Dr. W. M., 127

Béchamp, 280

Betulase, 132

Becker’s patent, 227

Bibliography, 282

Bile, 31

---- action of, 159

---- colouring matters, 30

---- salts, effect on puer, 46

---- ---- ---- ---- lipase, 142

Bird dung bate, 52

---- excreta, composition of, 53

Boehringer’s patent, 194

Bone meal, 196

Books of reference, 89, 282

Bran bacteria, 240

---- ---- pure cultures of, 269

---- composition of, 257

---- drench, 233

---- ---- non-volatile bodies in, 254

---- ---- products of fermentation, 247

---- ---- sweet, 263

---- ---- volatile bodies in, 249

---- ferments, action on starch, 258

Brown, Adrian J. Prof., 274

Butyric acid, 11

---- ---- fermentation, 111

Calcium in enzymes, 136

---- phosphate, 45

Carlsberg vessel, 170, 214

Caroubinase, 132

Casease, 132

Castor-oil seed, 188, 232

Catalysts, 127

Cellulose fermentation, 110

Cerealin, 245, 260

Chemical composition of puer, 24

---- deliming, 5

Chloroform, use of, in pancreatin solution, 151

Cholesterol, 30

Collagen, 56

Colloidal state, 57, 137

Concentration of salts in bate, 47

Condenser, Abbe’s, 87, 88

---- dark ground, 87

Conductivity of puer liquors, 80, 81

Copenhagen conference, 180

Cultivation of bating bacteria, 199

Culture medium, 105, 207

Cytase, 132

Deliming, chemical, 5

Density of skin, 60

Dermiforma, 189

Dextrin, 259, 261

Diastase, 128, 131, 132

---- Krawkov’s method of preparing, 135

Diastatic enzymes, 235

Digestive ferments, 148

---- juices, 230

Dog dung, analyses of, 26, 150, 152

---- bacteria in, 89, 98

---- detecting adulteration of, 144

---- fresh, bacteria in, 102

---- influence of food on, 28, 95, 153

---- method of analysis, 25

Dog dung, separating enzymes from, 134

---- trypsin in, 134

Doerr and Reinhardt’s laboratory, 32

Drench, acid “turning” of, 237

---- acids in, 156

---- action of, 233, 242, 245

---- artificial, 263

---- bacteria in, 239

---- damage, 236

---- fermentations of, 238

---- gases from, 242, 248

---- glucoses in, 261

---- “pinholey,” 238

---- putrid “turning” of, 237

---- sweet bran, 235

Dressing hides, 19

Drop culture, 87

Dung analyses, 26, 150, 152, 153

---- mineral matter of, 153

Eberle, G., 13

Eberle’s patent, 221

Effront, Dr., 11

Eitner, 242, 244

Electrometric apparatus, 76

---- method, 33, 49

Emulsin, 132

Enzymatic bates, 197

Enzymes, action of, 145

---- ---- of serum on, 144

---- ---- on skin, 140

---- calcium in, 136

---- defined, 127

---- diastatic, 235

---- from bacteria, 131

---- hydrolysing, 132

---- in dog’s dung, 137

---- lipolytic, 145

---- manganese in, 136

---- preparation of, 134, 164

---- proteolytic, 145

Erepsin, 133, 142

Erodin, 179

Erodin, stock liquor, 182

Esco, 192

Esters, synthesis of, 127

Ethyl butyrate, 165

Ethylamine butyrate, 42

---- lactate, 42

---- propionate, 42

Fahrion, Dr., 52

Falling, 67

---- apparatus for measuring degree of, 82

Fat in puer, 25, 30

---- in skins, 16

Feeding of dogs, 28, 95

Fermentation in the leather industry, 147

---- nitrogen from, 279

Ferments, digestive, 148

---- gall, 224

---- hydrolysing, 132

---- imino-lytic, 133

---- oxidizing, 133

---- oxylytic, 133

Flagellæ, staining of, 94

“Flaked” grain, 149

Formic Acid, 9

Fractionating acids, 250

Frankland and Frew, 249

Gall ferments, 224

Gamgee, 281

Gas analysis, 247

Gases from drench, 242, 248

---- from pure cultures, 275

---- intestinal, 281

Gayon, 280

Gelatin, 56

---- density of, 63

---- glucose, 267

---- molecular weight of, 56

---- peptonized, 168

Glucose bate, 179

---- gelatin, 267

Glucoses in drench, 261

Glycerin, 141

Goat skins, 183

---- ---- bating of, 231

Guano, analysis of, 150

Golding, J., 175

“Grains,” analysis of, 7

Harness backs, 17

Hauff, J., 236

Hen dung, analysis of, 150

Hexoses, 125

Hide-powder, density of, 66

Hides, bating of, 17

Houston, Dr., 93, 94, 97

Hydrogen from drench, 239

Hydrogen-ion concentration, 74, 79

Hydrochloric acid, use in deliming, 11

Hydrolysis, 128

---- velocity of, 130

Hydrolysing enzymes, 132

Immendorf, 280

Imino-lactic ferments, 133

Indol, 95, 106

Infusoria, 123

Intestinal gases, 281

---- juice, 225, 228

Inulase, 132

Jean, F., 41

Jones, Arnold Seymour, 75, 133

Kaolin, 176

Kathreiner, F., 46, 236

---- bate trials by, 183, 184

Koch’s Jahresbericht, 125

Körner, Dr. Th., 67, 167

Kossel, Dr. A., 170

---- and Dakin, 133

Kral, Prof., xv

Kühl, Dr. H., 236

Laccase, 133, 135

---- manganese in, 135

Lactase, 132

Lactic acid, 10

---- ---- from _B. furfuris_, 272

Lamb, M. C., 9

Law’s volumenometer, 61

Lecithin, 141

Lederer’s bate, 196

Lime in sheep grains, 23, 37

---- in puer liquors, 36, 40, 44

---- soaps, 16

Limed skin, 5, 7

Lion’s dung, 29

Lipase, 132, 141

---- effect of bile salts on, 142

Lipolytic enzymes, 145

Liquor pancreaticus, 189

Malase, 133

Maltase, 132

Manganese in enzymes, 136

Mastering, a term for puer, 3

Mercaptans, 46

Measuring truck, 8

Meggitt, Loxley, 171

Metchnikoff, 93

Mineral matter of dung, 153

Minot, Prof., 81

Mixed cultures, 173

Molecular weight of gelatin, 56

Monads, 123

Morocco leather, 3

Moulds, 114, 126

Müller, 72

Muscle, contraction of, 73

Myrosin, 132

Myxomycetes, 116

Nencki, 107

Nitrogen from fermentation, 279

---- in bran, 234

---- in puer liquors, 48

Nitrites, use of, in bating, 193

Non-electrolytes, influence of, 72

Nördlinger’s bate, 194

Nowak’s patent, 194

Nuclein, 114

Oake’s bate, 195

Oenoxydase, 133

Olease, 133

Organic acids, use in deliming, 13

---- ---- in puer, 155

Oropon, 140, 186, 219

Osmosis, 58

Osmotic pressure, 59, 167

O’Sullivan, J., 244

---- and Thompson, 128

Oxalic acid fermentation, 111

“Oxidizing” skins, 193

Oxydin, 133

Oxylytic ferments, 133

Paddle, 14

Pancreas, 220

Pancreatin, action on skin, 138, 151

Papain, 132

Parker, Dr. Gordon, xv, 11

Pectase, 132

Pentoses, 125

Pepsin, 132

---- action on skin, 138

Peptolytic ferments, 119

Peptonized gelatin, 168

Phosphates in the bate, 43

Phosphorbutyralin, 195

Pigeon dung, 103

“Pinholey” drench, 238

Plasmase, 132

Plate cultures, 103

Popp and Becker’s patent, 197

Precipitin, 144

Pribram, Dr., 73

Procter, Prof. H. R., 10, 55, 205, 210

Proteolytic enzymes, 145

---- ferments, 119

_Proteus_ bacteria, 118

Puer, amido compounds in, 156

---- chemical composition of, 24

---- fat in, 25, 30

---- organic acids in, 155

---- quantity used, 15

---- reactions of, 31

---- wheel, 13

Puerine, 190

Puering, solution of skin substance in, 47

Pure cultures of bran bacteria, 269

Purgatol, 192

Purin bases, 30

Putrefaction, 116

---- _See_ Nos. 58 to 78 of Bibliography, 282

---- mechanism of, 107

---- of meat, 120

Putrefactive bacteria, 107

Putrid “turning” of drench, 237

Reaction of puer, 31

Rennet, 128, 132

Rhamnase, 132

Rogers, Dr. Allen, 195

Röhm’s patent, 219

Ruge, 281

Sabatier and Senderens, 127

Salt solution, physiological, 87

Salts solution, 267

Sand, Dr., xv, 33, 81

Schorlemmer, K., 186

Scud, 51

Scudding, 16

---- machine, 17

Serum, action of, on enzymes, 144

Shearling pelts, 183

Shrewsbury, H. S., 166, 281

Simon’s bate, 195

Skatol, 46

Skin substance, ash of, 39

Skin substance, density of, 60

---- ---- fat in, 16

---- ---- solution of, 47, 51

Soerensen, Prof., 43, 80

Solid matter in bate, 73

---- ---- influence of, 175

Soluble matter of bate, 176

Soyka’s dilution method, 103

_Spirillum volutans_, 112

---- _delsulfuricans_, 124

Spongy leather, 238

Staining and mounting, books on, 89

---- of flagellæ, 94

Starch, action of bran ferments on, 259

Steapsin, 132

Stiasny, Prof. E., 282

Sucanine, 191

Sucrase, 128, 132

Sulphuric acid, use in deliming, 11

Sulphuretted hydrogen, 46

“Sweating” bacteria, 105, 213

Sweet bran drench, 235

Swelling, 67

---- alkaline, 72

Symbiosis, 269

Synthesis of esters, 127

Syntonin, 32

Thio-acids, 196

Tiffany’s bate, 179

Toxins, 143

Trehalase, 132

Trent bridge laboratory, 107, 252

Trimethyl-amine, 107, 252

---- butyrate, 42

Trypsin, 132, 133

Trypsin, in dog dung, 134

Turney, Sir John, scudding machine, 17

“Turning” of drench, 287

Tyrosinase, 133

Urea, 29

Urease, 132

Uric Acid, 29

Velocity of hydrolysis, 130

Volumenometer, 61

---- air, 67

---- Law’s, 61

Wladika, J., 256

Willcox, Dr. W. H., 243, 245

Wood’s American patent, 210

---- English patent, 205

Wool bacteria, 174

Xylose, 125

Yeast water, 259

Yoghurt, 236

Zinc, effect on growth of moulds, 113

Zollikoffer’s bate, 178

Zoogloæ, 242

Zymase, 133

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