Chapter L: Section IV: Miscellaneous Animal Proteins

The excreta of animals include animal proteins of great importance to agriculture and horticulture, forming the staple supplies of manure. The manure of animals should contain not only the solid waste material and undigested food, but also the urine, which contains much nitrogen, and hence makes considerable difference to the value of the product as a fertilizer. If the animals are fed on rich foods, the manure obtained is correspondingly richer, especially in its protein content.

The value of dung manures depends not merely upon the protein content, but also upon its content of phosphate and potash, as well as other organic matter. The protein breaks down into simpler nitrogenous compounds, and eventually, through ammonium carbonate, it becomes nitrate. Nitrogenous manures darken leaves and increase growth considerably. Dung manures are deficient in phosphates and potash and are of value partly as nitrogenous manures producing growth, and partly as dressings of organic matter for soil. From both points of view it is desirable that the manure should be well decayed. Fresh dung manures are both wasteful and injurious to soil, except perhaps to very stiff clays. They are wasteful inasmuch as much ammonia escapes, and injurious inasmuch as they cause the "denitrification" of the valuable nitrates already in the soil. When possible dung manures should be kept under cover. Free exposure to air and rain will sometimes reduce its value by one half. It should be stored until "sweet," and until the straw has rotted and become "short." This takes usually several months. A ton of well-rotted farmyard manure contains very approximately 10-12 lbs. nitrogen, about the same amount of potash, and about half that quantity of phosphates. It is, however, very variable. Horse manure is rather richer than cow manure, but more liable to loss on storage. Pig manure is intermediate between them. Sheep manure is distinctly richer in protein, and has therefore greater value as nitrogenous fertilizers. Poultry droppings are richer still, perhaps partly because they include the urinary products. When fresh they contain 18-25 lbs. nitrogen, 12-24 lbs. phosphate, and 6-12 lbs. potash per ton. When dried they have about double the value. Pigeon manure is even richer, and the pigeon loft scrapings have a manurial value about double that of dry hen manure, and eight times that of farmyard manure. Guano is much decayed droppings of sea birds on the tropical coasts of Africa and America. The supplies are now quite exhausted, and the market guanos are chiefly artificial fertilizers.

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There is one other animal protein which must be referred to before this volume is concluded, viz. silk. This is obtained from the cocoon of the "silkworm," which is the general name given to the larvæ of certain bombycid moths. These larvæ feed on the leaves of the mulberry, and when ready to pupate produce a considerable supply of a soft and delicate thread which is wound round about the larva itself. This is the raw silk, and it is unwound from the cocoon in a machine called the "silk-reel," and may then be wound into a thread. Two or more threads twisted together form "thrown-silk." Silk threads are also woven into cloth of characteristic texture and appearance. This protein thus forms the raw material of one of the most important textile industries.

* * * * *

From the fish trade there is much animal protein, which is useless for food purposes and which, to avoid nuisance, it is necessary to convert promptly in fertilizers. During the herring season there is the disposal in this way of the heads, tails, and the guts. Many fish are incidentally caught which, being valueless as food, are yet useful as manure. After the extraction of oil from fish livers the residue is suitable for a similar purpose. These residues are steamed, dried, and ground up, forming fish manure, rich in nitrogen and often also in phosphate.

REFERENCES.

"Chemical Fertilizers and Parisiticides," S. H. Collins, M.Sc.

"Organic Nitrogen Fertilizers," Part III., Section II., p. 105.

"Fish Manure," p. 110.

INDEX

Acclimatization in colloid systems, 236

Acid, ellagic, 29
gallic, 29
sulphurous, 227, 243

Acid process for bone gelatine, 243

Acids, for deliming, 23
for pickling, 114
in sour liquors, 29, 44

Adsorption, law of, 43
methods of clarification, 234
nature of, 41
of ions by gelatine, 211

African hides, 15

Albumins, 4, 240, 274, 277

Algarobilla, 32

Alum, 236, 240

American hides, 14

Animal excreta, 279

Arsenic sulphide, 20

Asiatic hides, 14

Astringency of liquors, 44

Bacteria in soaks, 16
limes, 20
bates, 24
tan liquors, 29

Bag leather, 86

Band-knife splitting, 52

Bark, hemlock, 34, 40
mallet, 34
mangrove, 35, 41
mimosa, 33
oak, 34
pine, 34, 41
willow, 32

Basic dyestuffs, 97

Basils, 115

Bating, 24, 94

Belting leather, 65

Blair-Campbell evaporator, 249

Bleaching leather, 62
glue, 241

Block Gambier, 40

Bloom, 29

Boiling process for glue, 223

Bone gelatine, 223
manure, 273
meal, 224

Bones, 223

Bookbinding leather, 104, 106, 117, 120

Boric acid, 23

Bottle tannage, 103

Box calf, 156

Bridle leather, 71

British hides, 8

Brushing leather, 63

Buck leather, 181

Buff leather, 181

Buffing, 52

Burning in, 54

Butt, 22

Bye-products of the gelatine trade, 272
of the leather trades, 268

Calcium sulphydrate, 22

Calf skins, 76, 120, 156

Casein, 276

Cast glue, 257

Catechin, 32

Catechol tans, 32

Caustic soda, 18, 20

Centrifugal fan, 50

Chamois leather, 181

Cheeks, 268

Chemistry of colloids, 201

Chestnut extract, 36

Chlorine bleach for glue, 246

Chrome calf, 156
goat, 163
hide, 170
sheep, 163

Chrome tannage, 127-174
finishing operations, 153
general methods, 139
history of, 127
one bath, 149
special qualities of, 136
theory of, 129
two-bath process, 142

Clarification of gelatine, 234

Coefficient of conductivity, 253

Colloid chemistry, 201

Combination tannages, 191

Concentrated foods, 275

Condenser water, 251

Conductivity coefficient, 253

Continental hides, 14

Crown leather, 178

Cube gambier, 40

Curing hides, drying, 13
dry-salting, 13
freezing, 13
salting, 12
sterilizing, 14

Currying, 49

Cut glue, 257

Decolorization of glue, 238

Deerskins, 92, 181

Degreasing bones, 224, 227
leather, 115

Deliming, 23

Depilation, 19

Divi-divi, 32

Dongola leather, 191

Drenching, 25, 95

Dressing leather, 24, 65-92

Drum stuffing, 53
tanning, 63

Drying gelatine and glue, 255
hides, 13
leather, 50

Dung bates, 24
manures, 279
puers, 94

Dyeing leather, 96

Ears, 220, 268

Eggs, 276

Elastic fibres, 6, 272

Ellagic acid, 29

Enamelled leather, 123

Enzymes, 24, 25, 94, 95

Erodin, 94

Evaporation, 37, 248

Evaporators, Blair Campbell, 249
Kestner, 249
Yaryan, 249

Evolution of gelatine industry, 265
of leather industry, 194

Extraction of gelatine and glue, 230-233
of grease, 115, 224, 227
of phosphate, 224
of tannin, 35

Extracts of meat, 275
of tanning material, 37-41

Faces, 220, 268

Fan drying gelatine, 257
leather, 50

Fat liquoring, 154
tannages, 178

Federation of Tanners, 108

Fellmongering, 113

Fermentation in bates and puers, 24, 94
in drenches, 25
in limes, 20, 21

Fertilizers, 269, 279

Filter press, 238

Finger test, 218

Finishing chrome leather, 153
heavy leather, 49
light leather, 96

Fish glue, 228
manure, 280

Fleshing, 22

Flocculation, 237

Food proteins, 274

Foods, concentrated, 275
dried, 277

Formaldehyde tannage, 185

Fractional extraction of glue, 230

Galalith, 277

Gallic acid, 29

Galls, 32

Gambier, 40

Gelatine, bleaching, 241
clarification of, 234
decolorization, 234
drying of, 255
evaporation of, 248
extraction of, 230
properties of, 200
raw material for, 220
uses of, 260

Glacé calf, 156
goat and sheep, 163

Glazing, 97, 155

Glove leather, 174

Glue (_see_ GELATINE)
difference from gelatine, 241

Goatskins, 99, 163

Graining, 97

Grease in bones and scutch, 224, 227
in skins, 115

Guano, 278

Hair, removal of, 22

Handlers, 47

Hard-grain morocco, 117

Harness leather, 71, 170

Heavy leather, 7-92
chrome leather, 170

Helvetia leather, 179

Hemlock bark, 34

Hides, American, 14
African, 15
Asiatic, 14
British, 8
Continental, 14
dried, 13
dry-salted, 13
fresh, 8
frozen, 13
salted, 12

Hoofs, 268

Horns, 268

Hyaline layer, 272

Hydrophile colloids, 240

Hydrophobe colloids, 240

Hydrosulphite of soda, 245

Hypo bath, 128, 147

Imitation box calf, 159
glacé kid, 163

Imperial aspect of leather trade, 198

Increase in strength of tan liquor, 44

Incrustation, 254

Influence of Lyotrope series, 206-209

Intensive production, 194, 265

Interfibrillar substance, 24

Iron and logwood, 75, 83, 109

Jacking leather, 51

Japanned leather, 123

Jelly, 203, 258

Keratins, 4
of epidermis, 272

Kestner evaporator, 249

Kid skins, 163, 174

Kips, 8, 76, 159

Lactic acid, 23

Lambskins, 110, 163, 174

Larch bark extract, 41

Layaways, 47

Layer, hyaline or glassy, 272

Layers, 47

Leaching, 35

Leather, definition of, 27

Legging leather, 76

Levant grain, 109

Lime, function of, in depilation, 20

Liming for chrome leather, 127
glue pieces, 220
hides, 18
leather, 83
skins, 92

Liquor, chrome 127, 129, 143-153
lime, 18-22
tan, 35

Logwood, 75, 83, 109

Lyophile colloids, 201

Lyophobe colloids, 201

Lyotrope series colloids, 206-209

Machine fleshing, 23
scudding, 23
shaving, 52, 82

Mallet bark, 34

Mangrove bark extract, 41

Mean temperature difference, 252

Meat extracts, 275

Mellow lime liquors, 18-21
tan liquors, 44

Memel butts, 83

Milk, 276

Mimosa bark, 33

Miscellaneous proteins, 266, 279
tannages, 174

Mixed tannage of sole leather, 55

Mordants, 96

Morocco leather, calf, 120
goat, 99
seal, 106
sheep, 110

Motor butts, 170

Multiple-effect evaporation, 249

Myrabolans, 30

Nature of chrome leather, 127
of leather, 27

Nett adsorption, 215

Neutralization, 153

Nitrogen in proteins, 1
value of manures, 280

Noses, 268

Oak bark, 34

Oakwood extract, 37

Offal for sole leather, 63

Oil tannage, 181

One-bath chrome tannage, 149

One-pit system of liming, 19

Open-vat system of extraction, 231

Oxidation method of bleaching, 245

Paddles for washing, puering, dyeing, and tanning, 17, 94, 96, 103

Parker, on valonia, 31

Pelt, preparation of, 16, 92, 139

Peroxides for bleaching, 246

Phlobaphenes, 33

Phosphate of lime, 223, 225, 273

Picking band butts, 90

Pickling foods, 275
skins, 114

Pigskins, 92

Pine bark, 34

Plumping, 19, 44

Precipitation, 236

Predigested foods, 276

Preparation of pelt, 16, 92, 139

Press leach, 35

Principles of chrome tannage, 139
clarification of gelatine, 234
liming, 92
vegetable tannage, 41

Procter, definition of leather, 27
glucose chrome liquor, 152
on gelatine swelling, 217
on pickling, 115

Properties of chrome leather, 127
gelatine and glue, 200

Protective colloid, 237

Proteins, classification, 3
composition of, 1-3
food, 274
miscellaneous, 266, 279
of dermis, 271
of epidermis, 272

Puering, 94

Purification of grease, 227

Putrid soaks, 18

Pyrogallol tans, 28

Qualities of chrome leather, 127
gelatine and glue, 200

Quebracho extract, 38

_Quercus ægilops_, 30
_robur_, 34

Quick processes of evaporating, 248
of tanning, etc., 194

Rabbit skins, 221

Raw material for gelatine, 220
heavy leather, 7
light leather, 92

Reds, 33

Reduction bleaching of glue, 243

Refrigerator, 258

Roans, 117

Rockers, 46

Roller leather, 118

Rolling leather, 51

Round of pits, 19, 46

Rounding pelt, 22

Salted food proteins, 275
hides, 12

Samming, 50

Satin leather, 76

Schultz chrome tannage, 128

Scouring, 51

Scudding, 22

Scutch, 271

Sealskins, 106

Seasoning, 97

Semi-chrome, 191

Sharp limes, 19

Shaving, 51

Shearlings, 114

Shedwork on gelatine, 257
on leather, 50

Sheepskins, 110, 163, 174, 181

Short processes, 47, 194

Silk, 280

Skins, 92

Skivers, 116

Sludge from lime pits, 270

Smoked foods, 275

Soaking hides, 16

Soda, 18, 20

Sodium sulphide, 18, 20

Sole leather, 55

Sour tan liquors, 44

Split fleshes, 76, 181
hides, 86

Splitting, 52

Staking, 155

Stocks, 18

Stoning, 51

Stove drying, 105, 109, 125

Strap butts, 65

Striking leather, 51

Stuffing leather, 49, 53

Substance, interfibrillar, 24

Sulphide of arsenic, 20
soda, 18, 20

Sulphurous acid, 227, 243

Sumach, 31
use in dyeing, 104, 117
use in finishing, 62, 84
use in tanning, 102

Suspenders, 46

Sweating, 113

Swelling of gelatine, 201-220
of pelt, 19

Syntans, 188

Synthetic tanning materials, 187

Tannage, alum, 174
bag, 103
bottle, 103
chrome, 127, 139
combination, 191
drum, 47
fat, 178
formalin, 185
oil, 181
with synthetic materials, 187
of bag leather, 86
of bridle leather, 71
of belting leather, 65
of harness leather, 71
of bookbinding leather, 99, 110, 120
of morocco leather, 99, 106, 110, 120
of picking band leather, 90
of sole leather, 55
of upper leather, 76
of roller leather, 118

Tannage, chrome, of calf, 156
of goat and sheep, 163
of hides, 170

Tannage, vegetable, heavy hides, 55-90
skins, 92-123

Tanning, theory of, 41
chrome, theory of, 129

Tannins, catechol, 32
classification of, 28
properties of, 27
pyrogallol, 28

Three-paddle system of tanning skins, 103

Three-pit system of liming, 19

Tissue, adipose, 271

Two-bath chrome tannage, 142

Udders, 220

Unhairing, 22, 23

Upper leather, 76, 115, 120, 123

Vacuum on condenser, 250
pan, 248

Valency rule, 131, 236

Valonia, 30

Vatting sole leather, 62

Vegetable tannage, 41
of hides, 55-90
skins, 92-123
tanning materials, 28

Velocity effect on heat transference, 253

War, effect on methods, 194, 265
on supplies, 11-13, 33, 277

Warble fly, 10

Waste leather, 270

Wattle or mimosa bark, 33

Waxed leathers, 76-86

Weather drying, 49

Willow bark, 32
calf, 156

Wood, J. T., action of puer, 94

Wool, 110, 269

Yaryan evaporator, 249

Zones of compressed water, 202-205