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 tannage[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[270]
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]
Tannage, 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]
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]