Principles and Practice of Fur Dressing and Fur Dyeing

Fur dyes of American make being equal in every way to the German product, show the same color reactions with the various mordants. The following table shows the shades produced with the same mordants as above:

All these shades are produced by dyeing in a bath containing a neutral solution of the dye. Sometimes the dye comes in the form of a salt of a mineral acid, like hydrochloric or sulphuric acid, in which case a sufficient amount of an alkali, usually ammonia, is added to liberate the free base. According to the Cassella Co., German manufacturers of the Furrol brand of fur dyes, the dyeing can also be carried on in slightly alkaline or in slightly acid solution, a different series of shades being obtained in each instance. Ammonia is used to render the bath alkaline, and formic acid to make it acid. The most customary practise, however, is to use neutral solutions of the dyes.

For preparing the mordant solutions much smaller quantities of the metallic compounds are used than in the case of the vegetable dyes. With chrome mordants cream of tartar is always employed as an assistant, and occasionally also with copper and with iron mordants. With copper, and also with iron mordants no addition is made at all, or sometimes a small quantity of acetic acid is added. The temperature of the mordant solution is kept about 30° C., and the duration of the mordanting varies from 2–24 hours according to the depth of shade desired. The concentration of the solution may also be varied, it sometimes being just as well to use a strong mordant solution and less duration of mordanting. Chrome may be combined with copper, and iron may be combined with copper, but chrome and iron do not go together as mordants. Some typical average mordanting formulas are as follows:

or,

The killed skins are immersed in the mordanting solution, and allowed to remain the required length of time. They are then thoroughly rinsed to remove any excess of the mordant, and are hydro-extracted. Under no circumstances should mordanted skins be permitted to dry, for they would be unfit for use again.

The dyebath is next prepared by dissolving the necessary quantity of the dye, varying from 0.1 gm. to 10 gms. per liter. Then if the solution must be neutralized, the ammonia is added and the temperature of the bath is brought to 30–35° C. by the addition of cold water. This temperature is maintained throughout the dyeing operation. To the solution is added the oxidizing agent. Ordinary commercial peroxide of hydrogen containing 3% by weight is the usual oxidizer, although perborates have been suggested. 15–20 parts of peroxide of hydrogen for every part of dye are added, and the dye solution brought to the proper dilution. As soon as the dyebath is ready, the skins are entered, and worked for a short time to effect even penetration. They are then left in the dyebath for 2–12 hours or longer according to the depth of shade. After being satisfactorily dyed, the furs are rinsed thoroughly, hydro-extracted and dried and finished. Where the dye is to be applied by the brush to the tips of the hair, stronger dye solutions are used, the brushed skins being placed hair together and let lie for about 6 hours in order to permit the color to develop, after which the furs are dried and drum-cleaned.

Some shades, particularly black, have a tendency to rub off slightly. In order to overcome this, the dyed furs, after rinsing, are treated with a cold solution of ¹⁄₂ part of copper sulphate per 1000 parts of water, for 3–4 hours, then without rinsing, hydro-extracted and dried. Furs which have been tipped are brushed with a 1–2% solution of copper sulphate and dried. Care must be taken in this after-treatment, for the use of too strong a solution of copper sulphate, or too prolonged action of such a solution will materially alter the shade of the dyed fur.

A few typical formulas will serve to illustrate the general methods of employing the Oxidation Colors:

Brown Sable Imitation on Unsheared Rabbit

The skins are killed with soda, soured, and washed, then mordanted with

for 24 hours. Then washed, and dyed for 24 hours with

Wash and dry the skins, then brush the tips with

Black on Sheared Muskrat

The skins are killed with soda, soured, and washed, then chrome mordanted for 6 hours. Then they are dyed for 6 hours with

The dyed skins are washed and dried, then tipped with

Brown on Thibet Sheep Skin

The killed skins are mordanted for 6 hours with a chrome mordant, then dyed for 6 hours with

It is also possible to combine dyeings with the Oxidation Colors with Vegetable dyeings, or with Aniline Black. For example, if it be desired to produce an imitation skunk on a raccoon, and an exceptionally fast and intense and lustrous black on the tips of the hair, the skins are dyed in the bath with the Oxidation dyes, and the tips of the hair are brushed with a mixture such as described under Vegetable Colors for the production of French seal, as follows:

Imitation Skunk on Raccoon

The skins are killed with caustic soda, soured and washed, then mordanted with an iron-copper mordant as described, and then dyed with

After washing and drying, the dyed skins are brushed over with a mixture such as used for dyeing French seal with Vegetable Colors.

In a similar manner, the Oxidation Colors may be used to give a base color to furs dyed by the Aniline Black process.

It is apparent from these few illustrations that a great variety of shades can be produced, and the dyeing of imitations of the better class of furs on cheaper skins is a comparatively simple matter, after an understanding of the nature of the dyes has been obtained, and a certain amount of skill acquired in working with these dyes.

CHAPTER XVI
FUR DYEING
Coal Tar Dyes

In addition to the Aniline Blacks and the Oxidation Colors already discussed there are certain of the synthetic coal tar dyes such as are generally used in the dyeing of textiles, which can also be applied on furs. There are several classes of these dyes, varying somewhat in their nature, and consequently in their manner of application; in the main they produce bright shades, such as are but seldom used on furs, yet which may occasionally serve for the production of novel effects. Basic, acid and chrome colors are the types which can be employed.

Basic colors possess great fullness and tinctorial strength, but have a tendency to rub off, and the tips of the hair take a darker shade with these dyes than the rest of the hair. The addition of acetic acid and Glauber’s salt to the dyebath will result in a more uniform dyeing. On account of the comparatively poor fastness to rubbing and washing, basic dyes are used only for dyeing furs which are intended for cheap carpet rugs, such as sheep and goat. They may also find use in the production of light fancy shades on other white furs. The procedure is usually as follows: The furs are killed in the customary manner with soap and soda or ammonia, or if this is insufficient, with milk of lime. A soap-bath is then prepared containing 2.5–6 grams of olive-oil soap per liter of water. The temperature of the bath is brought to 40° C. To this is added the solution of the dyestuffs, prepared by mixing the required color or colors with a little acetic acid to a paste, and then pouring boiling water on the mixture until dissolved. Undissolved particles or foreign matter are removed by passing this solution through a cotton cloth or sieve, and the clear solution then mixed with the soap-bath. The well-washed skins are then entered into the dyebath and immersed for about half an hour, or until the desired depth of shade is obtained. They are then removed, pressed or hydro-extracted and dried. For the production of light shades, the following dyes may be used:

For cream, light sulphur-yellow, maize, salmon, etc.

• Combinations of
• Thioflavine
• Rhodamine B
• Irisamine G

For greenish-yellows

• Combinations of
• Thioflavine
• Victoria Blue B

For light pink

• Rhodamine B
• Irisamine
• Rose Bengal Extra N

For purple

• Methyl Violet 3B–6B
• Crystal Violet

For sky-blue

• Victoria Blue B

For white

• Victoria Blue B (Milk-white)
• Methyl Violet 3B–6B
• Crystal Violet (Ivory-white)

To produce very delicate shades, the moist dyed skins are subjected to a sulphur bleach overnight, to lighten the color, then rinsed, and dried. Full, brilliant shades may be obtained by dyeing in a bath of 40° C., acidulated with 2–3 grams of acetic acid per liter of solution, the following dyestuffs being suitable:

For yellow to orange

• Thioflavine
• Paraphosphine
• Rhodamine
• Safranine
• New Magenta O

For pink

• Rhodamine B
• Rose Bengal Extra N

For light red

• Safranines

For bordeaux and red

• Magenta
• New Magenta
• Russian Red
• Cerise

For violet

• Methyl Violet 6B–4R
• Crystal Violet 5B

For blue

• Victoria Blue B
• Methylene Blue BB
• New Methylene Blue N

For green

• Malachite Green Crystals
• Brilliant Green Crystals, or combinations of
• Thioflavine
• Diamond Phosphine
• Victoria Blue B

For brown

• Chrysoidines
• Bismarck Browns

In dyeing skins with harder hair than that of sheep or goat, mere killing is insufficient to render the hair capable of taking up the dye. The skins are therefore immersed before dyeing, in a cold, weak solution of chloride of lime, the affinity of the hair for the dye being thereby greatly increased.

Acid dyes are employed when a greater fastness is required than can be obtained with the basic colors. Sulphuric acid in a quantity equal to half the weight of the dyestuffs used, together with four times that quantity of Glauber’s salt is added to the dyebath. Formic acid may be used in place of the sulphuric acid, very good results being obtained. The skins are immersed in the dyebath, and worked until thoroughly soaked with the dye liquor, and then allowed to remain until the proper depth of shade is attained, or overnight. The temperature of the solution is about 40° C., and only very light shades can be produced in this manner. In 1900 and again in 1914, the Cassella Co., a large German manufacturer of dyestuffs, obtained patents for processes enabling the dyeing of furs in hot solution with the acid dyes. The method required that the skins be chrome-tanned in order to render them resistant to the action of hot solutions, the addition of a small amount of formaldehyde to the chrome solution increasing this effect. The skins are then treated with a solution of chloride of lime in order to increase the affinity of the hair for the dyestuffs. The method as it is now practised is as follows: The skins which have been cleaned and washed are chrome tanned by the method as described in the chapter on Tanning Methods, 60 grams of formaldehyde being added to every 10 liters of the chrome solution. After proper tanning the skins are rinsed, and while still moist they are subjected to a treatment with chloride of lime. They are first immersed for 15 minutes in a cold bath containing 120 grams of hydrochloric acid 32–36° Twaddell per 10 liters of water, then without rinsing, they are entered into a bath made up by adding gradually in four portions the clear solution of 2–4 grams of the chloride of lime per 10 liters of water. After working for an hour, the skins are removed and entered again into the acid solution, in which they are worked for another 15 minutes. In order to neutralize and remove the last traces of the chloride of lime from the furs, they are rinsed in a luke-warm bath containing 1–2 grams of sodium thiosulphate, or hyposulphite of soda, in 10 liters of water. The skins are then rinsed again, and hydro-extracted, or pressed, and are ready for dyeing. The dyebath is prepared with the required quantity of dye, to which is added 10–20% Glauber’s salt and 2–5% acetic acid (both calculated on the weight of the skins). The skins are entered at 20° C., then after three-quarters of an hour to 40° C., and then after another hour slowly to 50–55° C. For blacks, the temperature is raised as high as 65° C. After dyeing the skins are treated with a solution containing per 10 liters

for 15 minutes, then hydro-extracted and dried, without further rinsing.

For this method of dyeing, the following dyes may be used:

For yellow and orange

• Fast Yellow S
• Acid Yellows
• Naphthol Yellow S
• Tropaeoline
• Orange GG, R, II, IV

For reds

• Acid Reds
• Lanafuchsine
• Azo Orseille

For violet

• Azo Wool Violet
• Acid Violets

For blue

• Cyanole FF
• Azo Wool Blue
• Naphthol Blue R
• Formyl Blue B

For green

• Naphthol Green B
• Fast Acid Green
• Cyanole Green

For brown, combinations of

• Fast Yellow S
• Acid Yellows
• Tropaeoline DD
• Orange GG
• Lanafuchsine
• Indigo Blue N
• Cyanole B
• Fast Acid Green BN

For black

• Naphthylamine Blacks
• Naphthol Blacks
• Naphthol Blue-black

For grey

• Silver Grey N
• Dyed with the addition of ¹⁄₂–1% of alum

The chrome colors are dyed on furs when very fast shades are desired, all the fancy colors being produced in this manner, but for black, only the acid dyes are suitable. The preparation of the skin is exactly the same as for the acid colors, except that the treatment with chloride of lime may be omitted, although for very full shades it is desirable. The dyeing is carried out as follows: The dyebath is prepared with the requisite amount of the desired dyestuff, which is previously dissolved, and to this is added a solution of sodium bichromate, the amount of this substance being half the weight of the dye. The solution is heated and the skins entered and dyed for 1–2 hours at 70–80° C. Then the dyebath is exhausted by the addition of ¹⁄₃% acetic acid, the skins being worked for another half hour, then rinsed, hydro-extracted and dried. Any of the one-bath chrome, or after-chrome colors may be used for this method.

Recently methods have been patented for the dyeing of furs by means of the vat colors. Vat dyes are among the fastest coloring matters ever produced, and their application on furs would be a great advantage, if suitable shades could be obtained. The general process for dyeing with vat colors, consists in reducing the dye, which is usually very insoluble, into a soluble “leuco” compound, by means of hydrosulphites in the presence of alkalies. The leuco compound is not a dye itself, but when the fibre absorbs it, and is then exposed to the air, the leuco compound is reoxidized to its original insoluble form, which remains fast and permanent. The use of strong alkalies in vat dyeing has hitherto been a great obstacle in the use of these dyestuffs, but in 1917, the Farbwerke Hoechst, a large German dye works, patented a process as follows: “A process for dyeing furs with vat colors. The dyeing is done in solutions of the vat dyes (after the addition of gelatine or some other protective colloid), which are rendered neutral or only slightly alkaline with ammonia, by neutralizing the caustic soda of the solution of the leuco compound of the vat dyes by the addition of ammonium salts, or suitable acids. The dyeings thus obtained are uniform and fast, the leather is dyed to only a slight degree, and shows no deleterious effects of the dyebath on the tannage.” As a practical application of this process, another patent was taken out by the same company, also in 1917, as follows: “A process for producing fast blacks on furs, consisting of dyeing a ground color with appropriate vat dyes in a hydrosulphite vat, and after oxidation in air, topping with an Aniline or Diphenyl black. The dyeings obtained by the combination of vat dyes which are fast to oxidizing agents, with an oxidation black, have an appearance matching that of logwood black in beauty; and with a dark-blue to blue-black under-color, and a full, deep black top color, cannot be distinguished from logwood. These dyeings also have the advantage of being faster to light than logwood or other blacks.”

While these processes undoubtedly have many meritorious qualities which make them interesting, they do not seem as yet, to have attained any great practical application. However, it is a field of fur dyeing which is worth while developing, and with certain necessary improvements in these processes, the vat dyes may yet supersede partially some of the other methods of dyeing furs.

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.

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. 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.

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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