Chapter XVII: Bleaching of Furs

Bleaching is for the purpose of lightening the color of furs, and is most generally applied to white-haired skins such as white fox, ermine, and occasionally white lambs of all kinds, and white bears. Among such furs, pelts of a naturally pure white tone are relatively scarce, while in the majority of cases the color ranges from a pale creamy white to a decidedly yellowish shade. Colors which vary from the pure white detract considerably from the attractiveness and consequent value of the fur, and indeed, some pelts are so far off shade that they can only be used when dyed a darker color. Most white skins which are but slightly inferior in color can be brought to a pure white by bleaching, and they can then be used natural. Some pelts, on the other hand, are particularly resistant to the action of bleaching agents and cannot be sufficiently decolorized to render them suitable for use natural, so these are also dyed. For the production of certain delicate or fancy dyed shades on white furs, it is often necessary to bleach the skins in order to be able to obtain pure tones. Such instances are not very common, however. Occasionally dark furs, such as beaver, are bleached on the tips of the hair, a golden shade being obtained thereby, which at one time was quite popular, but recently such effects have not been in vogue.

In the bleaching of furs, two steps may be distinguished, first degreasing, and second, bleaching proper. In the preliminary operations of fur dressing, the furs are treated with soap or weak alkalies to cleanse them and to remove excess oil from the hair. During the various processes and manipulations, the hair, especially on white skins, may become soiled or somewhat greasy again, so it is advisable to repeat the cleaning process. This should in every case be as light as possible, using a weak solution of soap for the softer and cleaner pelts, or dilute solutions of ammonium carbonate or soda ash for the more greasy-haired skins. The skins are then thoroughly rinsed to remove all traces of the degreasing material. This step is very essential in order to obtain uniform bleaching.

Broadly speaking, there are two general methods which can be used in bleaching furs, one involving the use of what are known as reducing agents, and the other employing oxidizing substances.

Among reducing agents which can be used for bleaching furs are sulphurous acid, and its salts such as sodium bisulphite and sodium sulphite; hydrosulphites, and derivatives.

1. ~Sulphurous acid.~--When sulphur is burned, sulphur dioxide gas is formed. In the presence of moisture, or when dissolved in water, this gas forms sulphurous acid, which is one of the most commonly used bleaching chemicals for all sorts of materials, and is very effective for decolorizing furs. The procedure usually followed is to hang up the moistened skins on wooden rods in a more or less cubical chamber made of stone or brick, and lined with wood or lead. No other metals may be used, because they are quickly corroded by the sulphurous acid. The requisite quantity of sulphur is placed in a pot in the bleaching chamber, and then ignited, after which the doors are shut tight. The fumes of the burning sulphur in contact with the moist hair readily exert their bleaching action on the furs, and the operation is allowed to proceed for six or eight hours, or overnight. Then by means of fans or other devices, the air filled with sulphur dioxide gas is withdrawn from the chamber, and replaced by fresh air. The door is opened, the skins removed, exposed to the air for a time, then rinsed, and finally dried and finished. Sometimes one operation is not enough to sufficiently bleach the hair, so the process is repeated. Sulphur dioxide gas can now be obtained compressed in cylinders, which are more convenient to handle than burning sulphur. The flow of gas which is introduced into the bleaching chamber by means of a nozzle attached to the cylinder, can be regulated, and the bleaching thus retarded or accelerated.

2. ~Sodium bisulphite and sodium sulphite.~--These salts of sulphurous acid are effective in their bleaching action only when in solution in the presence of acids. The acids liberate sulphurous acid from the salts, so this method is virtually the same as 1. Instead of using the salts of sulphurous acid, sulphur dioxide may be dissolved in water, and the solution used for bleaching by immersing the furs in it. This procedure, while consuming somewhat less time than the chamber process, is more likely to affect the leather, which would have to be retanned. The principle is the same as that involved in method 1.

3. ~Hydrosulphites and derivatives.~--The bleaching agent can be prepared by adding zinc dust to commercial bisulphite of soda dissolved in about four times its weight of water until no more reaction is evident. Milk of lime is then added to precipitate the zinc, and the clear supernatant liquid of 1.5°–5° Tw. is used for bleaching. The skins are immersed for 12–24 hours, taken out, washed and finished. Instead of preparing the hydrosulphite, the commercial products may be used with greater convenience, a solution containing 1–4% of the hydrosulphite powder being used, and the skins treated in this until satisfactorily bleached.

The bleaching action of sulphurous acid and hydrosulphite is supposed to be due to the reduction of the coloring matter of the hair to a colorless compound; or possibly to the formation of a colorless compound of the bleaching material with the pigment. The former seems the more probable explanation, because the change is not a permanent one, the original natural color returning after a long exposure of the bleached fur to air and light. However, the results are sufficiently enduring to satisfy the requirements of the trade in the class of furs on which these methods of bleaching are used.

Bleaching chemicals with an oxidizing action generally used for decolorizing furs are hydrogen peroxide and peroxides; occasionally hypochlorites and permanganates are also used.

1. ~Hydrogen peroxide.~--Hydrogen peroxide is usually employed for bleaching in the form of its 3% solution, to which is added about 20 cubic centimeters of ammonia per liter. The ammonia serves partially to neutralize the acid which commercial peroxide generally contains, and also to facilitate the bleaching action. The thoroughly degreased skins are immersed in the solution until the hair is completely wetted by it, are then removed, and evenly pressed or hydro-extracted, after which the pelts are hung up to dry in the air. As the hair becomes drier, the concentration of the peroxide becomes greater, and consequently the bleaching action is stronger. Where there is a likelihood of the leather being affected by the bleaching solution, the ammoniacal peroxide may be applied to the hair with a fine sponge or brush until sufficiently wetted, and then hanging the skins up to dry. Repetition of the process is sometimes necessary to obtain pure white, but the results are always excellent.

2. ~Peroxides.~--The most important of these is sodium peroxide, which comes on the market as a yellowish-white powder, which must be kept dry, and away from any inflammable material, as fires have been caused by the contact of the peroxide with such substances. When dissolved in water, it is equivalent to a strongly alkaline solution of peroxide of hydrogen.

Na₂O₂ + 2H₂O = H₂O₂ + 2NaOH
sodium water peroxide caustic
peroxide of soda
hydrogen

When dissolved in acid, the alkali is neutralized, and a neutral solution of peroxide of hydrogen and a salt is obtained, and this method is used to obtain peroxide of hydrogen cheaply.

Na₂O₂ + H₂SO₄ = H₂O₂ + Na₂SO₄
sulfuric sodium
acid sulphate

3 parts of sodium peroxide are slowly dissolved in a cold 1% solution of 4 parts of sulphuric acid, stirring during the addition, and making the resulting solution neutral to litmus paper, acid or more sodium peroxide being added as needed. There is then added 3–6 parts of a solution of silicate of soda of 90° Tw. The skins are immersed until properly bleached, taken out, passed through a weak acid solution, then washed and finished. This method generally requires the leather to be retanned after bleaching. Another process, which involves the use of peroxides, but which is not commonly practised, consists in rubbing the hair with a pasty mixture of equal parts of water, barium dioxide, and silicate of soda, hanging up the skins to dry, and then beating and brushing the hair.

3. ~Permanganates.~--The only member of this group that finds practical application for bleaching purposes is potassium permanganate. The skins are immersed in a 0.1% solution of the crystals of potassium permanganate, until the hair acquires a deep brown color. They are then removed, rinsed, and entered into a second bath containing sulphurous acid in solution, prepared by acidifying a solution of sodium bisulphite. The skins are then worked in this until fully bleached. It is the permanganate which does the bleaching, the sulphurous acid being for the purpose of dissolving the brown compound of manganese formed on the hair.

4. ~Hypochlorites.~--Chloride of lime and sodium hypochlorite, which is prepared from the former, are the chief chemicals of this type used for bleaching. The skins are entered into a weak solution of the hypochlorite, and left until the hair is decolorized; then after removing, they are passed through a dilute acid, and subsequently through a weak solution of sodium thiosulphate in order to remove all traces of the hypochlorite. This method causes the hair to acquire a harsh feel, and the yellow color is never entirely eliminated. The hair, however, possesses a great affinity for certain types of dyestuffs, and it is only when these particular classes of dyes are to be applied to the furs, that the hypochlorite bleach is used. (See dyeing with Acid colors).

The various oxidation methods of bleaching are supposed to change the coloring matter of the hair into an entirely different and colorless compound which cannot return to its original form. The bleach is therefore permanent.

In common practise, the sulphurous acid, and the peroxide of hydrogen methods are the two chiefly employed in bleaching processes. Sulphurous acid is used to bleach the cheaper kinds of furs, while peroxide of hydrogen is applied to the finer furs.

Whichever process is used, it is customary to give the bleached skins a subsequent “blueing,” by passing them through a very weak solution of a blue or violet dye, such as indigo-carmine, crystal violet, alkali blue or ultramarine. The furs are then dried and finished off as usual. In drum cleaning white furs, gypsum or white sand, or sometimes even talc are used with the sawdust, or occasionally alone without the sawdust.

BIBLIOGRAPHY

Allen “Commercial Organic Analysis”

Armour, B. R. “Fur Dressing and Dyeing” 1919

---- Color Trade Journal, Vol. 1, p. 51–53

---- Jour. Amer. Leather Chemists’ Assn., Vol. 13, p. 63–69.

Belden, A. L. “Fur Trade in America” 1917

Beltzer, F. J. G. “Industrie des Poils et Fourrures, etc.” 1912

---- Revue Generale des Matieres Colorantes, Vol. 12, 1908

Bennett, H. G. “Manufacture of Leather” 1910

Bertram, P. Deutsche Färber-Zeitung 1895–96 Heft 17, p. 266

Bird, F. J. “American Practical Dyers’ Companion” p. 241–245

Boerner, H. Kunststoffe, 1912 p. 223

Brevoort, H. L. “Fur Fibres as shown in the Microscope” 1886

Bucher, B. “Geschichte der technischen Künste” 1875–1893

Cubaeus, P. “Das Ganze der Kürschnerei” 1912

Davis, C. T. “Manufacture of Leather”

Erdmann, E. Deutsche Färber-Zeitung 1894–95 Heft 21, p. 337

---- Zeitschrift für angewandte Chemie, 1895, Heft 14

---- Zeitschrift für angewandte Chemie, Heft 35, 1905

---- Berichte, 1904, 37, p. 2776, 2906

Farrell, F. J. “Dyeing and Cleaning” 1912

Fleming, L. “Practical Tanning” 1916

Fougerat, L. “La Pelleterie dans l’antiquité, la préhistoire, etc.”

Gardner, W. M. “Wool Dyeing” 1896

Grandmougin, E. Zeitschrift für Farben-Industrie, 1906, 5, p. 141

Gruene, E. Deutsche Färber-Zeitung, 1895–96 Heft 13, p. 197

Halle “Werkstätte der heutigen Künste,” 1762, Vol. 2, p. 317

Hartwig, O. L. “Sprengler’s Künste und Handwerke,” 1782

Hausman, L. A. Scientific Monthly, Jan. 1920; March, 1921

---- Natural History, Vol. 20, 4, 1920

---- American Journal of Anatomy, Sept. 1920

---- American Naturalist, Nov.–Dec. 1920

Hayes, A. H. National Cleaner and Dyer, Nov. 1920, p. 55–57

Jacobson, “Schauplatz der Zeugmanufacturen” p. 493

Jones, J. W. “Fur Farming in Canada” 1913

Knecht, Rawson & Loewenthal “Manual of Dyeing” 1916

Kobert, R. “Beitrage zur Geschichte des Gerbens und der
Adstringentien” 1917

Koenig, F. Zeitschrift für angewandte Chemie, 1914, Vol. 1, p. 529

Lamb, J. W. Jour. Soc. Dyers & Colourists Dec. 1905, p. 323

Lamb, M. C. “Dressing of Leather” 1908

---- Jour. Soc. Dyers & Colourists 1913, 29, p. 160–165

Larish & Schmid “Das Kuerschner Handwerk” 1–3

Laut, A. C. “The Fur Trade of America” 1921

Lightfoot, J. “The Chemical History & Progress of Aniline Black”
1871

Mairet, E. M. “A Book on Vegetable Dyes” 1916

Martin, G. “Industrial Organic Chemistry”

Matthews, J. M. “Application of Dyestuffs” 1920

Mayer, A. “Die Färberei in der Werkstätte des Kürschners”

Mierzinski, S. “Die Gerb und Farbstoffextrakte”

Noelting & Lehne “Anilin-Schwarz” 1904

Perkins & Everest “Natural Organic Coloring Matters” 1918

Petersen, M. “The Fur Traders & Fur-Bearing Animals” 1920

Poland, H. “Fur-Bearing Animals in Nature and Commerce”

Proctor, H. “Leather Industries Laboratory Book”

---- “Tanning”

---- “Making of Leather”

Schlottauer, E. Deutsche Farber-Zeitung 1911, Heft 20, p. 397

---- Deutscher Färber-Kalender 1911, p. 65

---- Leipziger Färber-Zeitung 1909, p. 441

Schmidt, C. H. “Handbuch der Weissgerberei”

Setlik, B. Deutsche Färber-Zeitung 1901, p. 213

Smith, R. W. Color Trade Journal Vol. 3, Sept. 1918, p. 304–310

---- Textile Recorder, Vol. 36, p. 292–293, Dec. 1918

---- Revue Generale des Matieres Colorantes, Vol. 23, p. 32–36

Stevenson, C. H. “U. S. Fish Commission Report 1902–1903”, Bulletin
No. 537

Stickelberger, E. “Geschichte der Gerberei” 1915

Strasser “Chemische Färberei der Rauchwaren” 1879

Ullmann “Enzyklopedie der technischen Chemie”

Villon, A. M. “Traité pratique de la fabrication des cuirs, etc.”
1900

Werner, H. “Die Kürschnerkunst” 1914

---- “Das Färben der Rauchwaren” 1914

Whittaker, C. M. “Dyeing with Coal Tar Dyes” 1919

Wiener, F. “Weissgerberei” 1877

Witt-Lehman “Chemische Technologie der Gespinst-Fasern” 1910

Zeidler, H. “Die moderne Lederfabrikation” 1914

INDEX

Acetate, aluminum, 118

---- chromium, 120

---- copper, 120

---- ferrous, 119

---- lead, 126

Acetic acid, 112

Acid dyes, 174

Acids, action of, on hair, 29

---- ---- on skin, 26

After-treatment with copper, 168

Alaska fox imitations, 143

Alkaline aluminum mordants, 122

---- chromium mordants, 123

---- iron mordants, 123

Alum, 32, 53, 118

---- chrome, 57

---- -chrome tans, 64

---- tans, 54, 56

Aluminum acetate, 118

---- mordants, 118

---- sulphate, 53, 118

Ammonia, 110

Ammonium sulphide, 126

Aniline black, 144

---- ---- by dip process, 154

---- ---- chemistry, 145

---- ---- Green’s process for, 152

---- ---- nature of, 144

---- ---- One-bath, 149

---- ---- Oxidation, 150

---- ---- processes, 149

---- ---- ungreenable, 148

Aniline oil, 145

Astrachan 5, 7, 12

Bacteria, 51

Badger, 7

Ball-drum, 62

Bandrowski’s base, 164

Basic dyes, 171

Beam, 38

Beaming, 38

Bear, black, 5, 7

---- brown, 5, 8

---- white, 8

---- ---- bleaching of, 179

Beating furs, 79

Beaver, 5, 8, 25, 83, 94

Beechwood ashes, 108

Bichromate of soda, 121, 147

Black, aniline, 144

---- ---- by Green’s process, 152

---- ---- chemistry of, 145

---- ---- nature of, 144

---- ---- One-bath, 149

---- ---- Oxidation, 150

---- ---- ungreenable, 148

Black, diphenyl, 152

---- logwood, 139

---- on Chinese goats, 141

---- on lambs, 141

---- on raccoon, 130

---- on skunk, 130

---- on wolf, 130

Bleaching of furs, 179

Blending, 91, 104

Blue-grey on white furs, 142

Blueing, 184

Blue salt, 120

---- vitriol, 119

Borax, 39, 58

Brasilein, 135

Brasilin, 135

Brazilwood, 135

Bright shades on furs, 171

Broadtail, 8, 12

---- dyeing of, 139

Brown on Thibet sheep, 169

---- with natural dyes, 142

Brush process, 98

Brushes used in dyeing, 100

Butter, 60, 63

Cage, 80

Cageing, 80

Campeachy wood, 133

Caracul, 8, 12

---- dressing of, 53

Caracul, dyeing of, 140

Carnivorous animals, furs of, 37

Cased skins, 36

Castor oil, 60, 63

Cat, civet, 5, 8

---- house, 8

Caustic soda, 44, 110, 113

Centrifugal machine, 40

Chamber drying, 73

Chamois dressing, 31

---- tan, 49, 58, 61

Characteristics of tans, 65

Chestnut extract, 133

Chinchilla, 5, 6, 8, 94

---- blending of, 91, 104

Chinchillone, 9

China goat, black on, 141

Chlorates, 147

Chloride of lime, 174

---- ---- bleach, 184

Chrome acetate, 120

---- alum, 57, 120

---- colors, 176

---- -copper mordant, 167

---- -formaldehyde tan, 64

---- tans, 57, 174

Chromium mordants, 120, 166

---- ---- alkaline, 123

---- salts in tanning, 53

Cleaning pelts, 40

Coal tar colors, 171

Cocoanut oil, 60

Cod-liver oil, 60

Collagen, 25

Colloidal solutions, 48

Combination tans, 49, 64

Conveying dyed skins, 104

Conveyor drying, 73

Copper acetate, 119

---- mordants, 119, 166

---- salts, 109

---- ---- after-treatment with, 168

---- sulphate, 119

Copperas, 119

Copper-iron mordant, 167

Coriin, 21

Corium, 21

Cortex, 23

Cottonseed oil, 60, 63

Cuba wood, 134

Cutch, gambier, 65, 135

Cuticle, 23

Davy, Sir Humphrey, 47

Degreasing furs, 179

Diphenyl black, 152

Dip process, 98

Dressing of lambs, 52

---- ---- rabbits, 54

---- ---- moles, 54

Drum, 80

Drum-cleaning, 105

Drumming, 76

Drying-oils, 60

Drying skins, 71

Durability of furs, 5

Dyeing furs at higher temperatures, 174

Dyeing of imitations, 93

---- ---- novelty shades, 92

---- with aniline black, 144

---- ---- coal tar colors, 171

---- ---- mineral colors, 125

---- ---- oxidation colors, 155

---- ---- vegetable colors, 128

Egg-yolk, 63

Emeraldine, 145

Enzymes, 51

Epidermis, 21

Erdmann, 155

Ermine, 5, 9

---- bleaching of, 179

Fahrion, 48

Fat-glands, 21

Fats, animal, 59

Fermentation, 51

Ferrous acetate, 119

Ferrous sulphate, 119

Finishing dyed furs, 104

Fisher, 9

Fitch, 9, 94

Flat skins, 36

Fleshing, 41

---- knife, 38, 42

---- machines, 42

Flesh side, 22, 37

Formaldehyde, 63

---- -chrome tan, 64

---- tans, 49, 63

Formic acid, 44, 50

---- ---- as soaking agent, 39

Fox, black on, 140

---- blue, 9

---- cross, 4, 10

---- grey, 10

---- kit, 10

---- red, 4, 5, 10

---- ---- dyed imitation silver fox, 137

---- silver, 4, 10

---- ---- imitations, 137, 143

---- white, 11, 94

---- ---- bleaching of, 179

French seal dye, 138, 144

Furamine dyes, 162

Fur beating machine, 80

Fur dressing, 30

Fur dyeing, 91

---- ---- difficulties of, 95

---- ---- with aniline black, 144

---- ---- with coal tar colors, 171

---- ---- with mineral colors, 125

---- ---- with oxidation colors, 155

---- ---- with vegetable colors, 128

Fur-hair, 24

Furriers’ guilds, 34, 90

Furrol dyes, 166

Furs, colors of, 3

---- description of, 7

---- durability of, 5

---- of carnivorous animals, 37

---- of herbivorous animals, 37

---- quality of, 3, 4

---- uses of, 1

---- valuation of, 6

---- weight of, 5

Fustic, 134

---- shades with, 135

Gall-nuts, 128, 132

Gambier cutch, 65, 135

Gelatine, 1, 25, 47, 48

Genet, 5

Glycerine, 63

Goat, 5, 11

---- logwood black on, 141

Green’s process for aniline black, 152

Grey-blue on white furs, 142

Ground water, 87

Guard-hair, 24

Guilds, furriers’, 34, 90

Hair, 22

---- action of acids on, 27

---- action of alkalies on, 28

---- action of salts on, 28

Hamster, 3, 11

Hardness of water, 87

Hare, 5, 11, 94

---- black on, 140

---- blue-grey on, 142

---- lynx dye on, 126

---- stone marten imitation on, 126

Hematein, 133

Hematoxylin, 133

Herbivorous animals, furs of, 37

Hudson seal, 144

Hydro-extraction, 40

Hydrogen peroxide, 168

---- ---- bleaching with, 182

Hydrosulphite bleach, 181

Hypochlorites, 184

Imitations, dyeing of, 93

Iron mordants, 119, 167

Iron pyrolignite, 119

Iron salts in tanning, 53

Iron tan, 58

Iron vitriol, 119

Kangaroo, 12

Keratin, 25

Kicker, 61

Killing, 98, 106

---- formulas, 108

---- nature of, 107

---- purpose of, 106

---- by brush process, 111

---- by dip process, 111

---- with caustic soda, 113

---- with lime, 112

---- with soda, 112

Knapp, 46, 57

Knife, beaming, 38

---- shaving, 38

---- fleshing, 38

Kolinsky, 5, 12

Krimmer, 5, 12, 13

Lactic acid, 44, 51

Lactic acid fermentation, 50

Lambs, 12

---- dressing of, 50, 53

---- dyeing of, 92, 140, 141, 142

Lard, 60

Lead, acetate, 126

Lead sulphide dye, 126

Leather, definition of, 48

---- dressing of, 30

Leopard, 5, 13, 94

---- tanning of, 43

Lima wood, 135

Lime, 108, 110, 112

Linseed oil, 60

Litharge, 109

Loft drying, 72

Logwood, 133

---- blacks, 139

---- shades with, 134

Lynx, 5, 13

---- imitation on rabbit and hare, 126

Luster of hair, 23

Machines used in brush dyeing, 102

---- ---- dip dyeing, 103

Marmot, 14, 68, 94

Marten, blending of, 91, 104

Marten, baum, 5, 14

---- stone, 5, 14

---- ---- imitation, 126

Medulla, 22

Meunier, 46

Mineral colors, 125

---- oils, 59, 63

---- tans, 49, 53

Mink, 5, 14, 68, 94

Mole, 5, 15

---- tanning of, 54

Monkey, 15

Mordanting, 98, 114

Mordants, alkaline, 121

---- aluminum, 118

---- chrome-copper, 167

---- chromium, 120, 166

---- copper, 119, 166

---- copper-iron, 167

---- iron, 119, 167

---- tin, 121

Mucines, 25

Muskrat, 5, 15, 68, 94

---- imitation seal on, 144, 169

Neats-foot oil, 60, 63

Neradol D., 64

Nigraniline, 147

Non-drying oils, 60, 63

Novelty shades, dyeing of, 92

Nutgalls, 33, 132

Nutria, 5, 15, 94

Oiling, 62, 77

Oils, drying, 60

---- non-drying, 50

---- partially-drying, 60, 63

Olive oil, 60

One-bath aniline black, 149

Opossum, 5, 15, 68

---- black on, 140

---- skunk imitation on, 138

---- seal imitation on, 144

Otter, River, 5, 16, 94

---- Sea, 5, 16

Over-hair, 24

Oxidation aniline black, 150

---- colors, 155

---- ---- shades with, 165

Para-amido phenol, 153, 157

Para-phenylene diamine, 153, 157, 162

Partially-drying oils, 60, 63

Pelage, 2

Pelt, 2

Pernambuco wood, 135

Peroxide of hydrogen, 168, 182

Peroxides, 182

Persian lamb, 5, 12

---- ---- dressing of, 50, 53

---- ---- dyeing of, 139

Physical theories of tanning, 47

Pickle, 49

Pigment granules, 23

Pony, Russian, 5, 16

Potassium permanganate as a dye, 127

---- ---- as a bleach, 183

Protective-hair, 24

Pyrolignite of iron, 119

Quercitron, 135

Quinone di-imine, 163

Rabbit, 6, 17, 94

---- imitation seal on, 144

---- lynx imitation on, 126

---- sable imitation on, 168

---- stone marten imitation on, 126

---- tanning of, 54, 65

Raccoon, 6, 17

---- black on, 140

---- skunk imitation on, 170

Rain water, 86

Red fox, dyed as silver fox, 137

Redwood, 135

Rodol colors, 165

Russian tan, 51

Sable, 6, 94

---- American, 17

---- blending of, 91, 104

---- imitation on rabbit, 168

---- Russian, 18

Salammoniac, 109

Salt, 32, 49

---- -acid tan, 49

---- -water soak, 39

Salts, neutral, 54

---- basic, 54, 115

Sawdust in drum-cleaning, 80

“Schrot-beize,” 50

Seal, 6, 18, 94

---- fur, 18

---- dyeing of, 92, 144

---- hair, 19

---- imitation on muskrat, 138, 169

---- -oil, 60

Shearing, 82

---- machine, 84

Shrinking-point of skins, 66

---- effect of chemicals on, 67

Silver fox imitations, 137, 143

Skin, 21

---- action of acids on, 26

---- action of alkalies on, 27

Skunk, 6, 19, 94

---- imitation on opossum, 138

---- ---- on raccoon, 170

Soaking skins, 39

Soda ash, 110, 112

Sodium bichromate, 121, 166

---- bisulphite, 127, 181

---- chloride, 49

---- peroxide, 182

---- sulphite, 181

Soft water, 87

Softening skins, 38

Souring, 113

Squirrel, 6, 19

Staking, 78

Stannous chloride, 121

Stiasny, 64

Stone marten imitation, 126

Stretching, 78

---- machines, 78

Sugar of lead, 126

Sulphonated oils, 63

Sulphuric acid, 49

Sulphurous acid bleach, 180

Sumach, 128, 133

---- tanning with, 33

Surface water, 87

Sweat-glands, 22

Tallow, 60

Tanned furs, qualities of, 48

Tanning methods, comparison of, 65

Tannins, 32, 132

Tiger, 19

Top-hair, 24

Train oils, 63

Tramping machine, 61

Turmeric, 136

Under-hair, 24

Under-wool, 24

Ungreenable aniline black, 148

Unhairing, 82

---- machine, 83

Ursol dyes, 157, 165

Vanadium compounds, 147

Vat dyes, 177

Vegetable dyes, 128, 136

---- oils, 59

---- tans, 49, 65

Verdigris, 120

Water, hard, 87

---- soft, 87

Whale oil, 60

White fox, bleaching of, 179

Wolf, 6, 19

Wolverine, 6, 20

Wombat, 20

Wood dyes, 128

Yellow wood, 134

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Transcriber’s Notes:

Punctuation has been standardised--in particular, missing periods and quotation marks have been supplied where obviously required. Three entries in the bibliography were located out of alphabetical order, and have been moved accordingly (Fougerat, Lamb, Martin). All other original errors and inconsistencies have been retained, except as follows:

Page 7: changed Enclyclopedia to Encyclopedia
(in Encyclopedia Britannica, 11th Ed.)
Page 20: changed Kaola to Koala
(Koala or Australian Bear.)
Page 62: changed partiular to particular
(on the particular fur treatment)
Page 67: changed degress to degrees
(almost 10 degrees higher than)
Page 73: changed samewhat to somewhat
(based on a somewhat different)
Page 93: changed imitatations to imitations
(dyeing of imitations to a great)
Page 101: changed diagramatically to diagrammatically
(and B shows diagrammatically, machines)
Page 128: changed conjuction to conjunction
(which in conjunction with certain)
Page 136: changed curcuma to Curcuma
(stem of the Curcuma tinctoria,)
Page 137: changed simutaneously to simultaneously
(and dye simultaneously; and third)
Page 140: changed atmopheric to atmospheric
(aid of the atmospheric oxygen.)
Page 142: changed followlowing to following
(successively in the following baths:)
Page 149: changed ozidizing to oxidizing
(is also an oxidizing agent and)
Page 154: changed dryig to drying
(several times, drying each time at)
Page 161: changed manufacurers to manufacturers
(Other manufacturers of coal-tar)
Page 170: changed Racoon to Raccoon
(_Imitation Skunk on Raccoon_)
Page 185: changed Werkstatte to Werkstätte
(Halle “Werkstätte der heutigen)
Page 185: changed Gerben to Gerbens
(Geschichte des Gerbens und der)
Page 185: changed Astringentien to Adstringentien
(und der Adstringentien” 1917)