1. Liquid Extracts.—Liquid extracts shall be thoroughly stirred and mixed immediately before weighing, which shall be rapidly done to avoid loss of moisture. Thick extracts, which cannot be otherwise mixed, may be heated to 50° C., then stirred and rapidly cooled before weighing, but the fact that this has been done must be noted in the Report.

2. Solid Extracts.—Solid extracts shall be coarsely powdered and well mixed. Pasty extracts shall be rapidly mixed in a mortar, and the requisite quantity weighed out with as little exposure as possible, to avoid loss of moisture. Where extracts are partly dry and partly pasty, so that neither of these methods is applicable, the entire sample shall be weighed and allowed to dry at the ordinary temperature sufficiently to be pulverised, and shall then be weighed, and the loss of weight taken into calculation as moisture.

In such cases as gambier, in which it is not possible to grind, or by other mechanical means to thoroughly mix the constituents of the sample, it is permissible to dissolve the whole, or a large portion of the sample, in a small quantity of hot water, and immediately after thorough mixing to weigh out a portion of the strong solution for analysis.

3. Barks, and other Solid Tanning Materials.—The whole sample, or not less than 250 grms., shall be ground in a mill until it will pass through a sieve of 5 wires per centimetre. Where materials such as barks and divi-divi contain fibrous materials which cannot be ground to powder, the ground sample shall be sieved, and the respective parts which do and do not pass through the sieve shall be weighed separately, and the sample for analysis shall be weighed so as to contain like proportions.

Section III.—Preparation of Infusion.

1. Strength of Solution.—The tannin solution employed shall contain from 0·35 to 0·45 grms. per 100 c.c. of tanning matters absorbed by hide. (Paris 1900.)

2. Solution of Liquid Extracts.—A sufficient quantity shall be weighed into a covered basin or beaker, from which it shall be washed into a liter flask with boiling water and well shaken, and the flask shall be filled to the mark with boiling water. The neck being covered with a small beaker, the flask shall be placed under a cold water tap or otherwise rapidly cooled to a temperature between 15° and 20° C., and made up accurately to the mark, after which it shall be thoroughly mixed, and the filtration at once proceeded with.

Note.—Tannin infusions may be kept from fermenting by the addition of 3 to 5 drops of essential oil of mustard per liter. (F. Kathreiner.)

3. Filtration.—The filtration of the solution for analysis may take place through any paper which may be considered most suitable for the particular case, and with or without the use of kaolin, absorption of tanning matter, if any, being corrected for by an amount determined by a similar filtration of a clear solution. Perfectly clear solutions need not be filtered.

To determine the correction, about 500 c.c. of the tanning solution of the strength prescribed for analysis is obtained perfectly clear, preferably by the method of filtration which is to be corrected for. After thorough mixing, 50 c.c. is evaporated to determine “total soluble No. 1.” A portion of the remainder is then filtered in the manner for which correction is to be made, and 50 c.c. of the filtrate is evaporated for “total soluble No. 2.” Deducting No. 2 from No. 1 the difference is the correction required, which must be added to the total soluble found by analysis. It is generally advisable, both in analysis and in the second filtration for correction, to filter first 150 c.c. (which in analysis may be used for the determination of non-tannins), and then to employ the next 50 c.c. for evaporation, keeping the filter full during the operation; but whatever procedure is adopted must be rigidly adhered to in all analyses to which the correction is applied. Where kaolin is employed, a constant weighed quantity (1 or 2 grm.) must be used, which is first washed with 75 c.c. of the liquor by decantation, and then washed on to the filter with a further quantity of liquor, of which 200 c.c. is filtered as above.[191]

4. Solid Extracts.—Solid extracts shall be dissolved by stirring in a beaker with boiling water, the undissolved portions being allowed to settle, and treated with further quantities of boiling water, and the solution poured into a liter flask. After the whole of the soluble matter is dissolved, the solution is treated similarly to that of a liquid extract.

5. Extraction of Solid Materials.—Such quantities shall be weighed as will give an infusion of the strength already prescribed. (Preparation of Infusion, Resolution 1.) Not less than 500 c.c. of the infusion shall be extracted at a temperature not exceeding 50° C., after which the temperature shall be gradually raised to 100° C.,[192] and the extraction continued till the percolate is free from tannin and the whole made up to one liter, the weaker portions of the solution being first concentrated if necessary by evaporation in a flask, in the neck of which a funnel is placed.

Section IV.—Determination of Tanning Matters and Non-Tannins; etc.

1. Total Soluble Matter.—100 c.c.[193] of the clear filtered tanning solution, or a smaller quantity if the balance employed is of sufficient delicacy, shall be evaporated in an open weighed basin of platinum, hard glass, porcelain, or nickel, on the water-bath, and the basin shall afterwards be dried till constant in an air-oven, at a temperature of 100° to 105° C., or at a temperature not exceeding 100° C. in vacuo till constant, care being taken that no loss occurs by splintering of the residue. The use of the vacuum-oven for drying the residues is recommended when possible.

2. Determination of Non-Tannins.—That the filter method shall remain the official method until the next Conference, but that members be permitted to employ the chromed hide-powder method of the American Association of Official Agricultural Chemists of 1901 (Appendix C) where it is desired, the fact being clearly stated on the report that the A.O.A.C. method has been employed, and not that of the I.A.L.T.C. (Leeds, 1902, see note, p. 480.)

That the “bell form”[194] of filter, as described by Professor Procter, shall be employed; not less than 5 grms. of hide-powder be used; the hide-powder should be so packed in the tube that the detannised liquor shall come over at a rate of about one drop in two seconds; and the filtrate be rejected so long as it gives a turbidity with a clear tanning solution. The filtrate may be used for the determination of non-tannin so long as it gives no reaction with salted gelatine solution.[195] The first 30 to 35 c.c. should be thrown away, and the next 50 c.c. of detannised solution, or an aliquot part of it, evaporated in a weighed basin on a water bath, and then dried till constant in an air-oven at a temperature of 100° to 105° C., or, in vacuo, not exceeding 100° C.

3. Hide-Powder.—That the hide-powder must be sufficiently absorbent for use in the filter, and that in a blank experiment conducted with distilled water in the same way as an analysis, the residue from the evaporation of 50 c.c. should not exceed 5 milligrams.

The Freiberg Hide-Powder, made by Mehner and Stransky, containing between 10 and 20 per cent. of cellulose (as suggested by Cerych), is recommended by the Conference (LiÈge, 1901) and is very suitable for the filter method; but the powder, when analysed by the Kjeldahl method and calculated to 18 per cent. of moisture, must not contain less than 11·5 per cent. of nitrogen (Leeds, 1902).

4. Determination of Moisture and “Total Dry Matter.”—That the moisture in the sample be determined by drying a small portion at the temperature adopted in the determination of the “total soluble.” In extracts yielding turbid solutions which can be thoroughly mixed, it is generally preferable after mixing the solution and before filtration, to measure off and evaporate 50 c.c. for the determination of total dry matter (and moisture) in the same manner as the “total soluble.”

5. Statement of Results.—It is recommended, when full analysis is given, that the Statement should be made in the following manner:—

If other determinations are given they shall form a separate additional statement.

Density.—The statement of densities of extracts, etc., should be given as specific gravity in preference to arbitrary degrees, such as BaumÉ, Twaddell, etc.

Section V.—Colour Measurement.

Colour Measurement.—It is recommended that the method used by English chemists, namely, measuring with Lovibond’s Tintometer (as described by Professor Procter and Dr. Parker, Journ. Soc. Chem. Ind., 1895, 125), shall be used, and the results stated in units of red, yellow and black. The measurement may be made on the solution used for analysis, but must be calculated to one containing 0·5 per cent. of tanning matter, in a centimetre cell.

Analysis of Used Liquors.

It was decided at LiÈge, 1901, and Leeds, 1902,[196] that the “Shake Method” with chromed hide-powder, of the American Association of Official Agricultural Chemists, 1901 (A.O.A.C.), should be employed in the detannisation of used tanning liquors, as with these the filter method is apt to give too high results owing to the amount of non-volatile acids which they contain. The method of the A.O.A.C. is given in Appendix C.

Analysis of Spent Tans.

It was decided at Leeds, 1902, that spent tans must be analysed like fresh tanning materials; but where the prescribed strength of solution cannot otherwise be obtained it is permissible to concentrate the entire solution by evaporation. It is advisable, where suitable apparatus is available, to concentrate in vacuo; but failing this, an ordinary flask may be used, in the neck of which a funnel is placed.

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APPENDIX B.—THE DECIMAL SYSTEM.

The metrical system of weights and measures, and the Centigrade thermometer scale have been generally used throughout the book, as more international and scientific than the complicated systems still unfortunately in use in this country. They have been fully explained in the Author’s ‘Laboratory Book,’ p. 2; but as this is not always at hand, a short sketch may be permitted here.

The basis of the metrical system is the “meter,” which is approximately ¹/_10,000,000 of the distance from the earth’s pole to the equator, and is equal to 39·3708 English inches, and for many practical purposes may be roughly reckoned as 40 inches. The meter is divided into 10 parts or “decimeters,” 100 parts or “centimeters,” and 1000 parts or “millimeters.” The standard of capacity is a cube of 1 decimeter, or about 4 inches, and consequently contains 1000 cubic centimeters, and is denominated a “liter.” The standard of weight is 1 cubic centimeter of water (at 4° C.), which is called a “gram.” Hence 1 liter of water weighs 1 “kilogram,” or 1000 grams. 1 cubic meter of water contains 1000 liters, and weighs 1000 kilograms, or 1 metrical ton (2200 lb. English). For purposes of reduction, the following figures may be given:—

1	gram	=	15·431	grains.
1	lb. av.	=	453·6	grams.
1	liter	=	0·22	gallon.
1	gallon	=	4·543	litres.

Actual reduction is, however, generally unnecessary if the question be treated as one of proportion. Thus a solution of 1 gram per liter is of the same strength as one of 1 lb. per 100 gallons (1000 lb.), and very approximately, as one of 1 oz. avoirdupois per cubic foot. In the case of pits, it is often simplest to measure them directly with a meter rule; length, breadth and depth, measured in decimeters and multiplied together, giving the contents in liters, and, in the case of water, the weight in kilograms.

The Centigrade or Celsius thermometer divides the difference between the freezing and the boiling points of water into 100°. The following table gives the points at which its scale agrees without fractions with that of Fahrenheit:

Comparison of Centigrade and Fahrenheit Degrees.

°C.	°F.
-20	-4
-15	+5
-10	14
-5	23
0	32
5	41
10	50
15	59
20	68
25	77
30	86
35	95
40	104
45	113
50	122
55	131
60	140
65	149
70	158
75	167
80	176
85	185
90	194
95	203
100	212
105	221
110	230
115	239

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APPENDIX C.
OFFICIAL METHOD FOR ANALYSIS OF TANNING MATERIALS,
ADOPTED AT THE EIGHTEENTH CONVENTION OF
THE AMERICAN ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, 1901.

I. Preparation of Sample.

Barks, woods, leaves, dry extracts, and similar tanning materials should be ground to such a degree of fineness that they can be thoroughly extracted. Fluid extracts must be heated to 50° C., well shaken, and allowed to cool to room-temperature.

II. Quantity of Material.

In the case of bark and similar material, use such quantity as will give about 0·35 to 0·45 gram tannins per 100 c.c. of solution, extract in Soxhlet or similar apparatus at steam-heat for non-starchy materials. For canaigre and substances containing like amounts of starch use temperature of 50° to 55° C., until near complete extraction, finishing the operation at steam-heat. In case of extract, weigh such quantity as will give 0·35 to 0·45 gram tannins per 100 c.c. of solution, dissolve in 900 c.c. of water at 80° C., let stand twelve hours, and make up to 1000 c.c.

III. Moisture.

(a) Place 2 grams, if it be an extract, in a flat-bottom dish, not less than 6 cm. in diameter, add 25 c.c. of water, warm slowly till dissolved, continue evaporation and dry.

(b) All dryings called for, after evaporation to dryness on water-bath, or others, shall be done by one of the following methods, the soluble solids and non-tannins being dried under similar, and so far as possible identical conditions:

1. For eight hours at the temperature of boiling water in a steam bath.

2. For six hours at 100° C., in an air bath.

3. To constant weight in vacuo at 70° C.

IV. Total Solids.

Shake the solution, and without filtering immediately measure out 100 c.c. with a pipette, evaporate in a weighed dish, and dry to constant weight, at the temperature of boiling water. Dishes should be flat-bottomed, and not less than 6 cm. in diameter.

V. Soluble Solids.

Double-pleated filter paper (S. and S., No. 590, 15 cm.) shall be used. To 2 grams of kaolin add 75 c.c. of the tanning solution, stir, let stand fifteen minutes, and decant as much as possible. Add 75 c.c. more of the solution, pour on filter, keep filter full, reject the first 150 c.c. of filtrate, evaporate the next 100 c.c. and dry. Evaporation during filtration must be guarded against.

VI. Non-Tannins.

Prepare 20 grams of hide-powder by digesting twenty-four hours with 500 c.c. of water, and adding 0·6 gram chrome alum in solution, this solution to be added as follows. One-half at the beginning and the other half at least six hours before the end of the digestion. Wash by squeezing through linen, continue the washing until the wash-water does not give a precipitate with barium chloride. Squeeze thoroughly by hand, and remove as much water as possible by means of a press, weigh the pressed hide, and take approximately one-fourth of it for moisture determination. Weigh this fourth carefully and dry to constant weight. Weigh the remaining three-fourths carefully and add them to 200 c.c. of the original solution; shake ten minutes, throw on funnel with cotton plug in stem, return until clear, evaporate 100 c.c. and dry. The weight of this residue must be corrected for the dilution caused by the water contained in the pressed hide-powder.[197] The shaking must be done in some form of mechanical shaker. The simple machine used by druggists, and known as the milk-shake, is recommended.

Provisional Method.—To 14 grams of dry chromed hide-powder in a shaker glass add 200 c.c. of the tannin solution, let stand two hours, stirring frequently, shake fifteen minutes, throw on funnel with a cotton plug in the stem, let drain, tamp down the hide-powder in the funnel, return the filtrate until clear and evaporate 100 c.c.

VII. Tannins.

The amount of these is shown by the difference between the soluble solids and the corrected non-tannins.

VIII. Testing Hide-Powder.

(a) Shake 10 grms. of hide-powder with 250 c.c. of water for five minutes, strain through linen, squeeze the magma thoroughly by hand; repeat this operation three times, pass the last filtrate through paper (S. and S. No. 590, 15 cm.) till clear, evaporate 100 c.c. and dry. If this residue amounts to more than 10 mg. the hide must be rejected.

(b) Prepare a solution of pure gallo-tannin by dissolving 6 grams in 1000 c.c. of water. Determine the total solids by evaporating 100 c.c. of this solution and drying to constant weight. Treat 200 c.c. of the solution with hide-powder exactly as described in paragraph 6. The hide-powder must absorb at least 95 per cent. of the total solids present. The gallo-tannin used must be completely soluble in water, alcohol, acetone and acetic ether, and should not contain more than 1 per cent. of substances not removed by digesting with excess of yellow mercuric oxide on steam-bath for two hours.

IX. Testing Non-Tannin Filtrate.

(a) For Tannin.—Test a small portion of the clear non-tannin filtrate with a few drops of a 1 per cent. solution of Nelson’s gelatin. A cloudiness indicates the presence of tannin, in which case repeat the process described under VI., using 35 instead of 20 grams of hide-powder.

(b) For Soluble Hide.—To a small portion of the clear non-tannin filtrate add a few drops of the filtered tannin solution. A cloudiness indicates the presence of soluble hide, in which case repeat the process described under VI., giving the hide-powder a more thorough washing.

The temperature of solutions shall be between 16° and 20° when measured or filtered. All dryings should be made in flat-bottomed dishes of at least 6 cm. diameter, S. and S. No. 590, 15 cm. filter paper should be used in all filtrations.

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APPENDIX D.

The following Lists of Colours have been furnished by Mr. M. C. Lamb, Director of the Leather Dyeing Department of Herold’s Institute, London, who has devoted much time to testing the various dyes with regard to their permanence and suitability for leather. Many of the colours have also been tested and found satisfactory in the Leather Department of the Yorkshire College. The following abbreviations of makers’ names are used in the lists:—

B.	Basler Chemische Fabrik, A. G. Basle, Switzerland.
B.A.S.F.	Badische Anilin und Soda Fabrik. Ludwigshafen a. Rhine, Germany.
Ber.	Berlin Aniline Co. Berlin S.O., Germany.
B.S. Spl.	Brooke, Simpson & Spiller. Atlas Dye Works, Hackney Wick, London, N.E.
By.	Farben-fabriken, late Bayer & Co. Elberfeld, Germany.
C.	L. Cassella & Co. Frankfort a. Main, Germany.
C.A.	French Aniline Colour Works. Vieux-Conde (Norde), France.
C. & R.	Claus & RÉe. Clayton, near Manchester.
D.	Dahl & Co. Barmen, Germany.
D. & H.	Durand, Huguenin & Co. Basle, Switzerland.
G.	R. Geigy & Co. Basle, Switzerland.
Ger.	Gerber & Co. Basle, Switzerland.
K.	Kalle & Co. Bierbrich a. Rhine, Germany.
Leon.	A. Leonhardt & Co. Muhlheim a. Main, Germany.
Leitch	J. W. Leitch. Milnsbridge Chemical Works, Huddersfield.
Lev.	Levinstein Ltd. 21 Minshull Street, Manchester.
M.L.B.	Meister, Lucius & Bruning. Hoechst a. Main, Germany.
Mo.	Gilliard, P. Monnet & Gartier. Lyons, France.
N.	Noetzel, Istel & Co. Griesheim a. Main, Germany.
O.	K. Oehler & Co. Offenbach a. Main, Germany.
P.	St. Denis Dyestuff Co., late Pourier. St. Denis, near Paris.
R.	SociÉte Chimique des Usines du Rhone. Lyons, France.
R. H. & S.	Read, Holliday & Sons. Huddersfield.
S.C.Ind.	Society of Chemical Industry. Basle, Switzerland.
Uer.	Chemische Fabriken. Uerdingen a. Rhein, Germany.
W. Bros.	Williams Bros. & Co. Hounslow, Middlesex.

STAINING.

Single Acid Dyes suitable for Staining Vegetable Tanned Leather.

Browns.

• Solid brown. (M.L.B.)
• Acid brown. (W. Bros.)
• Brown A2. (B.S. Spl.)
• Brown A1. (B.S. Spl.)
• Mikado brown B. (Leon.)
• New acid brown. (B.S. Spl.)
• Bronze acid brown. (By.)
• Golden brown Y. (C.), (By.)
• Acid anthracene brown R. (By.)
• Fast brown N. (B.A.S.F.)
• Nut brown A. (C.)
• Fast brown. (By.)
• Fast brown G. (Ber.)
• Resorcin brown. (Ber.)
• Resorcin brown. (D.)
• Acid brown. (Ber.)
• Dark nut brown. (W. Bros.)
• Acid brown R. (C.)
• Acid brown R. (Uer.)
• Acid brown R. (R. H. & S.)
• New golden brown A1. (C.)
• Dark brown. (C.)
• Acid brown L. (B.A.S.F.)
• Acid brown D. (C.)

Yellows.

• Azo yellow. (Uer.)
• Phosphine subst. (B.S. Spl.)
• Chrysoine. (W. Bros.)
• Azo-acid-yellow. (Ber.)
• New phosphine G. (C.)
• Cuba yellow 2072. (S.C. Ind.)
• Cuba yellow (W. Bros.)
• Azo-flavine RS. (C.) and (B.A.S.F.)
• Azo-flavine 3R. (B.A.S.F.)
• Indian yellow R. (By.)
• Turmeric yellow. (G.)
• Solid yellow G. (Leon.)
• Solid yellow B. (Leon.)
• Indian yellow R. (C.)
• Cuba yellow. (C.)
• Napthol yellow S. (By.), (C.), (B.A.S.F.)
• Turmeric yellow. (C.), (G.)
• Fast acid yellow. (C.A.)

Reds and Oranges.

• Scarlet R. (By.)
• Crocein scarlet 3BN. (By.)
• Orange 2. (M.L.B.), (S.C. Ind.), (C.) and (B.A.S.F.)
• Orange 2B. (By.)
• Mandarin G extra. (Ber.)
• Brill. crocein M.O.O. (C.)
• Bordeaux G. (By.)
• Atlas orange. (B.S. Spl.)
• Bordeaux cov. (Ber.)
• Fast red 21528. (By.)
• Fast red A. (Leon.), (By.), (Ber.), and (B.A.S.F.)
• Bordeaux B. (M.L.B.)

Greens.

• Acid green extra conc. (C.)
• Guinea green B. (Ber.)
• Guinea green G. (Ber.)
• Acid green GG. (By.)
• Acid green BB. (By.)
• Acid green B. (By.)
• Acid green G. (By.)
• Acid green 000. (Leon.)
• Acid green extra. (By.)
• Acid green (Uer.)
• Acid green (R. H. & S.)
• Light green SF. (B.A.S.F.)
• Erioglaucine. (G.)

Violets.

• Acid violet 4RS. (Ber.)
• Acid violet 7B. (Ber.)
• Acid violet 6B. (By.)
• Formyl violet S4B. (C.)

Blues.

• Bavarian blue D.B. (Ber.)
• Marine blue o. (K.)
• Solid blue. (M.L.B.)
• Blue 1. (Lev.)
• Blue 2. (Lev.)
• Blue 3. (Lev.)

Single Basic Dyes
suitable for Staining Vegetable Tanned Leather.

Browns.

• Bismark brown GG. (C.)
• Chrysoidine AG. (O.)
• Bismark brown 2B. (K.)
• Bismark brown (By.)
• Bismark brown R.C.E. (Lev.)
• Bismark brown M. (By.)
• Vesuvine conc. (M.L.B.)
• Vesuvine conc. (B.A.S.F.)
• Bismark brown C extra. (Leon.)
• Bismark brown RS. (B.S. Spl.)
• Bismark brown 3762. (W. Bros.)
• Rheonine A. (B.A.S.F.)
• Rheonine N. (B.A.S.F.)
• Brown R. (G.)
• Brown G. (G.)
• Manchester brown. (C.)

Yellows.

• Acridine yellow NC. (Leon.)
• Phosphine N. (Ber.)
• Patent phosphine R. (S.C. Ind.)
• Leather yellow 6730. (C.A.)
• Auramine 2. (By.)
• Chrysoidine cryst. (B.S. Spl.) and (By.)
• Chrysoidine diamond cryst. (W. Bros.)
• Leather yellow o. (M.L.B.)
• Chrysoidine. (R. H. & S.)
• Leather yellow G. (M.L.B.)
• Leather yellow 6730. (C.A.)
• Patent phosphine G. (S.C. Ind.)
• Leather yellow DRR. (Ber.)
• Xanthine. (O.)
• Cannella G. (W. Bros.)
• Pure phosphine. (C.)
• New phosphine G. (C.)
• Cori-phosphine o. (By.)
• Para-phosphine R. (C.)
• Para-phosphine G. (C.)
• Leather yellow 374. (D.)
• Leather yellow 375. (D.)
• Homo-phosphine G. (Leon.)
• Phosphine ABN. (Leon.)
• Auramine 2 patent. (S.C. Ind.)

Greens.

• Methyl green cryst. (Ber.)
• Methylene green. (M.L.B.)
• Solid green. (Leon.)
• Malachite green. (Ber.), (M.L.B.), (P.), (C.A.), (S.C. Ind.), (R. H. & S.), (Lev.), (C.), (B.S. Spl.) and (K.)

Reds.

• Safranine. (M.L.B.), (B.A.S.F.), (S.C. Ind.) and (K.), (Ber.), (By.), (C.A.), (Leon.), (Uer.)
• Russian Red. (By.) and (Ber.)

Violets.

• Methyl violets. (Ber.), (By.), (M.L.B.), (R. H. & S.), (B.S. Spl.), (C.) (S.C. Ind.), (P.) and (D.).

Blacks.

• Corvoline B. (B.A.S.F.)
• Corvoline G. (B.A.S.F.)

DYEING.

Single Acid Colours
suitable for Dyeing Vegetable Tanned Leathers.[198]

Yellows.

II.	Napthol yellow S. (Ber.), (B.A.S.F.), (By.) and (C.).
VII.	Quinoline yellow. (Ber.), (By.) and (B.A.S.F.).
II.	Citronine. (Leon.)
IV.	Solid yellow G. (Leon.)
IV.	Solid yellow B. (Leon.)
V.	Indian yellow S.
V.	Azo-acid yellow.
IV.	Indian yellow T. (C.)
VII.	Indian yellow R. (By.) and (C.).
IV.	Indian yellow G. (By.) and (C.).
IV.	Cuba yellow. (C.), (W. Bros.) and (S.C.Ind.).
V.	Azo-flavine RS. (B.A.S.F.) and (C.).
V.	Azo-flavine 3R. (B.A.S.F.) and (C.).
VI.	Circumein extra. (Ber.)
VII.	Tartrazine. (B.A.S.F.)

Oranges.

V.	Orange 2. (B.A.S.F.), (C.), (M.L.B.), (S.C. Ind.), (P.) (W. Bros.) and (By.).
V.	Mandarin G extra. (Ber.)
V.	Crocein orange. (K.) and (By.).
VI.	Ponceaux 10RB, 4R, Bo, 4RB, 6RB. (Ber.), (By.) and (D.).

Bordeaux.

VII.	Azo bordeaux. (By.)
IV.	Bordeaux B extra. (By.)
VI.	Bordeaux G. (By.)
V.	Bordeaux Y. (W. Bros.)
V.	Acid maroon. (M.L.B.) and (B.S. Spl.).
VIII.	Chromatrop 6B. (M.L.B.)

Reds.

V.	Fast red A. (Ber.), (By.), (B.A.S.F.), (B.S. Spl.) and (Leon.)
VIII.	Fast red S. (M.L.B.)
VI.	Fast red 21528. (By.)

Scarlets.

V.	Crocein scarlet R. (By.) and (K.).
V.	Crocein scarlet 2R. (By.)
VII.	Fast scarlet B. (B.A.S.F.), (W. Bros.) and (K.)

Browns.

IV.	Acid brown R. (C.)
V.	Acid brown L. (B.A.S.F.)
V.	Acid brown Y. (S.C. Ind.)
IV.	Acid brown D. (C.), (B.A.S.F.)
IV.	Acid brown (R.H. & S.)
IV.	Acid brown 4601. (B.S. Spl.)
V.	Acid brown D. (C.)
VII.	Resorcin brown. (Ber.)
V.	Acid brown. (Uer.)
IV.	Acid brown R. (Ber.)
VIII.	Acid brown Y. (M.L.B.).
VI.	Solid brown o. (M.L.B.)
V.	Fast brown. (By.)
V.	Fast brown. G. (Ber.)
V.	Fast brown. N. (B.A.S.F.)
IV.	Fast brown. 3B. (Ber.)
V.	Bronze acid brown. (By.)
VIII.	Acid anthracine brown R. (By.)
V.	New acid brown. (B.S. Spl.)
VI.	Dark nut brown. (Uer.)
IV.	New golden brown A1. (C.)

Blacks.

IV.	Napthol blue black. (C.)
V.	Napthylamine black 4B. (C.)
V.	Napthylamine black 6B. (C.)
VII.	Phenol black S. (By.)
IV.	Phenylamine black 4B. (By.)
VII.	Victoria black B. (By.)

Blues.

VIII.	Fast blue R. (Ber.)
VIII.	Bavarian blue DB. (Ber.)
V.	Erioglaucine. (G.)
IV.	Cyanole ext. (C.)
IV.	Marine blue. (K.)
VII.	Water blue N. (B.A.S.F.)
VIII.	Water blue 4 B. (Ber.)
VII.	Cotton blue II. (By.).
VII.	Toluidine blue. (B.A.S.F.) and (By.).
VII.	Water blue R. (Leon.)
VII.	Water blue 3R. (Leon.)
VII.	Water blue BTR. (B.A.S.F.)

Violets.

	Acid violets (Lev.), (B.A.S.F.) and (By.)
IX.	Acid violets 4R. (B.A.S.F.)
V.	Acid violets R. (C.)
V.	Acid violets R. (B.A.S.F.)
VI.	Acid violets 3BA. (M.L.B.)
IV.	Acid violets 3BN. (Lev.)
II.	Acid violets 6B. (By.) and (C.).
III.	Formyl violet S4B. (C.)

Greens.

IV.	Acid green extra conc. (C.)
IV.	Guinea green B and G. (Ber.)
IV.	Acid green ext. (By.)
IV.	Acid green GG ext. (By.)
IV.	Acid green 225. (By.)
IV.	Acid green BB. ext. (By.)
IV.	Acid green o. (M.L.B.)
IV.	Acid green 5677. (B.S. Spl.)
V.	Capri green 2G. (Lev.)

Single Basic Dyessuitable for Dyeing Vegetable Tanned Leathers.

Browns.

IV.	Vesuvine ooo ext. (B.A.S.F.)
II.	Vesuvine B. (B.A.S.F.)
II.	Vesuvine (C.)
III.	Vesuvine conc. (M.L.B.)
III.	Bismark brown ext. (Ber.) and (B.S. Spl.).
III.	Bismark brown ext. M. (By.)
III.	Bismark brown F. (By.)
IV.	Bismark brown YS. (B.S. Spl.)
III.	Bismark brown PS. (C.)
III.	Bismark brown GG. (C.)
III.	Bismark brown O. (L.)
III.	Bismark brown G. (O.)
III.	Bismark brown (S.C. Ind.)
III.	Bismark brown NYY. (W. Bros.)
III.	Bismark brown o. (M.L.B.)
II.	Cannella. (B.S. Spl.)
II.	Cannella. (B.A.S.F.)
II.	Cannella. (C.)
V.	Cannella. (S.C. Ind.)
II.	Cannella S. (Ber.)
III.	Cannella P. (W.)
IV.	Nanking. (B.A.S.F.)
IV.	Nanking. (R.H. & S.)
IV.	Nanking. (S.C. Ind.)
III.	Lavilliere’s 122. (By.)
II.	Rheonine. (B.A.S.F.)
IV.	Xanthine. (O.)

Yellowish Oranges.

III.	Chrysoidines, (Leitch); R, (R.H. & S.)
IV.	Chrysoidines ext. (W.).
II.	Chrysoidines (S.C.Ind.); GG,(C.)
III.	Chrysoidines G. (Leon.)
II.	Chrysoidines RE. (Lev.)
III.	Chrysoidines YY. (C.)
III.	Chrysoidines cryst. (B.S. Spl.)
III.	Chrysoidines G. (By.)
V.	Chrysoidines cryst. (C.A.)

Yellows.

III.	Auramine 2. (B.A.S.F.)
III.	Auramine. (S.C. Ind.)
III.	Auramine. (G.)
III.	Auramine. (Ber.)
III.	Auramine. (By.)
III.	Auramine. (L.)
III.	Auramine. (W.)
III.	Auramine. (C.)
III.	Auramine. (W.)
V.	Auramine conc. (M.L.B.).
IV.	Phosphine E. (B.A.S.F.)
IV.	Phosphine L. (B.A.S.F.)
IV.	Phosphine G. (Ber.)
IV.	Phosphine. (O.)
IV.	Phosphine. (C.)
IV.	Phosphine Ext. (M.L.B.)
IV.	Phosphine B ext. (S.C. Ind.)
III.	Phosphine III., II., I. (Leon.)
III.	Phosphine N. (Ber.).
V.	Cori-phosphine. (By.)
V.	Homo-phosphine. (Leon.)
V.	Para-phosphine. (C.)

Greens.

III.	Methyl green cryst. (By.) D.
V.	Methylene green o. (M.L.B.)
II.	Diamond green B and G. (B.A.S.F.)
II.	Benzal green. (O.)
II.	Brillt. green cryst. (M.L.B.)
II.	Brillt. green cryst. (By.)
II.	Brillt. green cryst. (O.)
II.	Brillt. green cryst. (L.)
II.	Brillt. green cryst. (Lev.)
II.	Brillt. green cryst. (Uer.)
II.	Brillt. green cryst. (S.C. Ind.)
II.	Malachite green. (B.S. Spl.)
II.	Malachite green. (Ber.)
II.	Malachite green. (C.A.)
II.	Malachite green. (K.)
II.	Malachite green. (M.L.B.)
II.	Malachite green. (Lev.)
II.	Malachite green. (G.)
II.	Malachite green. (O.)

Blues.

VII.	Methylene blue B, 2B and R. (Ber.)
VII.	Methylene blue. (B.A.S.F.)
VII.	Methylene blue. (M.L.B.)
VII.	Methylene blue. (Lev.)
VII.	Methylene blue. (C.)
VII.	Methylene blue. (C. & R.)
VIII.	New methylene blue. GG. (C.)
VIII.	New methylene blue. BB. (C.)
IV.	New blue R. (Ber.)
V.	New blue R. (By.)
VI.	New patent blue 4B. (By.)

Violets.

IV.	Methyl Violet 4B. (B.A.S.F.)
IV.	Methyl Violet 4R. (K.)
IV.	Methyl Violet 4R. (C.)
IV.	Methyl Violet 3B. (By.)
IV.	Methyl Violet 3B. (Ber.)
IV.	Methyl Violet 2B. (M.L.B.)
IV.	Methyl Violet (D.)
IV.	Methyl Violet 6B. (Leon.)
IV.	Neutral violet ext. (C.)

Bordeaux.

IV.	Magenta WB. (Leon.)
IV.	Magenta 3B. (Ber.)
IV.	Magenta RE. (Leon.)
IV.	Magenta WBG. (Leon.)
IV.	Magenta. (M.L.B.)
IV.	Magenta. (K.)
IV.	Magenta. (B.A.S.F.)
IV.	Magenta 4128. (B.S. Spl.)

Reds.

VIII.	Rhodamine B extra. (Ber.)
VIII.	Rhodamine B. (B.A.S.F.)
VIII.	Rhodamine B. (By.)
VIII.	Rhodamine (S.C. Ind.)
VIII.	Rhodamine (M.L.B.)
VII.	Safranine. (B.A.S.F.)
IV.	Russian red G. (B.A.S.F.).
IV.	Russian red B. (C.)
IV.	Russian red (Ber.)
IV.	Russian red (Uer.)
IV.	Russian red B. (B.A.S.F.)
IV.	Russian red G. (C.)
IV.	Russian red (Ber.)
IV.	Russian red R. (By.)
IV.	Cardinal 4B. (By.)
VIII.	Rhoduline red. (By.)
V.	Safranine G ext. (C.)
VII.	Safranine BS. (By.)
	Safranine G ext. (Ber.)

Acid Mixtures suitable for Dyeing and Staining
Vegetable Tanned Leathers.

• Orange 2. (M.L.B.)
• Azo-yellow o. (M.L.B.)
• Patent blue V. (M.L.B.)
• Resorcin brown. (Ber.)
• Circumein ext. (Ber.)
• Nigrosine 105. (Ber.)
• Acid brown R. (C.)
• Indian yellow G. (C.)
• Pure soluble blue. (C.)
• New acid brown. (B.S. Spl.)
• Phosphine subst. (B.S. Spl.)
• Induline. (B.S. Spl.)
• Acid brown R. (C.)
• Azo-flavine R.S. (C.)
• Naphtol blue black. (C.)
• Resorcin brown, (Ber.)
• Fast brown G. (Ber.)
• Napthylamine black D. (C.)
• Fast brown G. (Ber.)
• Circumine ext. (Ber.)
• Nigrosine 105. (Ber.)
• Fast brown. (By.)
• Indian yellow R. (By.)
• Fast green blue shade. (By.)
• Acid anthracene brown. (By.)
• Indian yellow R. (By.)
• Fast green blue shade. (By.)
• Fast brown N. (B.A.S.F.)
• Azo-flavine RS. (B.A.S.F.)
• Light green S.F. (B.A.S.F.)
• Dark nut brown. (Uer.)
• Azo-yellow. (Uer.)
• Acid green. (Uer.)
• Acid brown. (D.)
• Crocein orange. (D.)
• Cotton blue 3R. (D.)
• Resorcin brown. (D.)
• Cotton blue 3R. (D.)
• Acid brown B. (S.C. Ind.)
• Cuba yellow 2072. (S.C. Ind.)
• Acid green. (S.C. Ind.)
• Resorcin brown. (W. Bros.)
• Cuba yellow. (W. Bros.)
• Acid green. (W. Bros.)
• Napthol brown. (Leon.)
• Citronine A. (Leon.)
• Acid green 000. (Leon.)
• Acid brown R. (R.H. & S.)
• Acid yellow. (R.H. & S.)
• Nigrosine cryst. (R.H. & S.)
• Orange 2. (P.)
• Yellow oS. (P.)
• Acid green J3E. (P.)
• Acid brown. (C.A.)
• Acid yellow S. (C.A.)
• Pure blue cryst. (C.A.)
• Resorcin brown. (Ber.)
• Azo-acid-yellow or Circumine ext. (Ber.)
• Bavarian blue DB, or Guinea green G. (Ber.)
• Indian yellow R. (C.)
• Acid brown R. (C.)
• Pure soluble blue. (C.)
• Azo-acid-yellow conc. (M.L.B.)
• Solid brown o. (M.L.B.)
• Fast blue o sol. (M.L.B.)
• Bronze acid brown. (By.)
• Indian yellow R. (By.)
• Fast green blue shade. (By.)
• Acid anthracene brown. (By.)
• Indian yellow R. (By.)
• Fast green blue shade. (By.)
• Orange 11. (B.A.S.F.)
• Scarlet GL. (B.A.S.F.)
• Light green SFYS. (B.A.S.F.)
• Azo-flavine RS. (B.A.S.F.)
• Acid brown L. (B.A.S.F.)
• Light green SFYS. (B.A.S.F.)
• Chocolate. (Uer.)
• Tartrazine, (B.A.S.F.); or Azo-yellow, (Uer.)

Basic Mixtures suitable for Dyeing and Staining
Vegetable Tanned Leathers.

• Bismark brown M. (By.)
• Auramine 2. (By.)
• Methylene blue BB. (By.)
• Rheonine A. (B.A.S.F.)
• Vesuvine B2. (B.A.S.F.)
• Diamond green G. (B.A.S.F.)
• Bismark brown O. (Leon.)
• Auramine 2. (Leon.)
• Solid green P. (Leon)
• Bismarck Brown ext. (Ber.)
• Philadelphia yellow R. (Ber.)
• Malachite green cryst. (Ber.)
• New phosphine G. (C.)
• Chrysoidine. (C.)
• New blue B. (C.)
• Phosphine ext. (F.)
• Chrysoidine diamond cryst. (F.)
• Bright green cryst. ext. (F.)
• Bismark brown GG. (O.)
• Aniline yellow ext. (O.)
• Neutral violet ext. (O.)
• Dark brown B. (By.)
• Auramine 2. (By.)
• Emerald green cryst. (By.)
• Phosphine 3RB. (Ber.)
• Philadelphia yellow R. (Ber.)
• Russian green 36784. (Ber.)
• Bismark Brown RS. (B.S. Spl.)
• Cannella. (B.S. Spl.)
• Malachite green. (B.S. Spl.)
• Vesuvine conc. (M.L.B.)
• Auramine conc. (M.L.B.)
• Methylene green. (M.L.B.)
• Cutch brown. (Leitch.)
• Lemon yellow G. (Leitch.)
• Russian green 3 B. (Leitch.)
• Bismark brown 2 B. (K.)
• Yellow for leather ext. (K.)
• Malachite green cryst. (K.)
• Auramine. (G.)
• Brown R. (G.)
• Malachite green. (G.)
• Auramine o. (Lev.)
• Bismark brown R.C.E. (Lev.)
• Brill. green. (Lev.)
• Bismark brown Y40. (R.H. & S.)
• Canary 2. (R.H. & S.)
• Green cryst. Y. (R.H. & S.).
• Leather brown A. (S.C. Ind.)
• Auramine 2. (S.C. Ind.)
• Leather black 1. (S.C. Ind.)
• Leather black R. (Uer.).
• Yellow 4803. (Uer.)
• Blue black S. (Uer.)
• Bismark brown NYY. (W. Bros.)
• Cannella G. (W. Bros.)
• Brown for leather 375. (D.)
• Fast yellow 168. (D.)
• Methyl green G ext. fine. (D.)
• Brown N. (D.)
• Leather brown P. (D.)
• Paris violet o. (D.)

Chrome Leather.

The following dye-stuffs are suitable for dyeing chrome leather. The leather after tanning, is boraxed in the usual manner and then mordanted by drumming or paddling in a tannin solution; for dark shades 3 per cent. gambier and 3 per cent. fustic extract (the weight being calculated on the leather struck out after boraxing) is suitable; for light shades 1¹/₂ per cent. gambier is to be recommended. The leather, after mordanting, is fat-liquored and dyed, adding a weight of sodium or potassium bisulphate equal to that of the dye-stuff, to the dye-bath. The following is not by any means a complete list of the dyes which will dye chrome leather well, but merely representative.

After the goods are dyed, they should be well washed in tepid water to which has been added a little common salt; one pound to every three dozen skins being a suitable amount to use. When the goods have been washed, they are struck out by machine and are then ready for shaving, if the operation has not been performed previous to dyeing. The skins are afterwards nailed out flat, grain-side up, on boards, and a mixture of glycerine and water—3 lb. of glycerine dissolved in one gallon of water being a suitable strength—is well sponged on the grain-side; the goods are now lightly oiled (using a good sperm, neat’s-foot or mineral oil), before being taken to the drying room. When thoroughly dry they are taken off the boards, and placed with layers of damp sawdust between each skin, for a few hours in order to allow the goods to become suitably damp for staking. The skins should now be well staked by machine, the Haley (England), Slocomb or Vaughn (America) being good machines for this purpose (p. 192).

After staking, the goods are “soft-boarded,” and a thin coat of a weak linseed mucilage is applied to the skins, which are afterwards dried out and seasoned with the following mixture:—

“Soak 10 to 15 oz. of dry egg albumen for four hours in 1 gallon of cold water, with occasional stirring, strain off any insoluble matter and add 1 gallon of milk. A little carbolic acid (phenol) may be added to the above if it is desired to keep the finish for more than two or three days—1 oz. of phenol previously dissolved in a little water, added to each gallon of the finish, being a suitable amount.” A little dye should be added to the mixture.

After seasoning, the skins are dried out in the stove, glazed twice round and re-seasoned with the above mixture diluted with its own volume of water. The goods are dried out and again glazed, perched lightly, and finally boarded up from neck to tail in order to raise the popular straight-grain. Should the glaze be too bright the albumen solution may be reduced to half-strength.

When the goods have been glazed they are rubbed over on the grain side with a flannel cloth which is slightly damp with linseed oil, trimmed up, and are ready for sale.

Dyes Suitable for Dyeing Chrome-Tanned Leather.

Browns.

• Resorcin brown. (Ber.)
• Chocolate. (Uer.)
• Fast brown. (BY.)
• Fast brown. (Ber.)
• New golden brown A.1. (C.)
• Fast brown. (B.A.S.F.)
• Acid brown Y. (S.C. Ind.)
• Acid brown B. (S.C. Ind.)
• Golden brown. (Leitch.)
• Bronze acid brown. (By.)
• Light nut brown. (Uer.)
• Resorcin brown. (W. Bros.)
• Acid brown 5210. (W. Bros.)
• New acid brown. (B.S. Spl.)
• Light nut brown. (R.)
• Brown 2Y. (R.)
• Azo-phosphine. (Uer.)
• Golden brown Y. (W. Bros.)

Yellowish Browns and Yellows.

• Citronine. (Leon.)
• Azo-flavine RS. (B.A.S.F.)
• Cuba yellow 2072. (S.C. Ind.)
• Phosphine substitute. (B.S. Spl.)
• Azo-yellow conc. (M.L.B.)
• Azo-flavine. (R.)
• Golden orange R. (Leitch.)
• Circumein ext. (Ber.)
• Indian yellow G. (By.)
• Turmeric substitute (W. Bros.).
• Azo-yellow R. (M.L.B.).
• Chrysophenin G. (Leon.)
• Indian yellow T. (C.)
• Quinoline yellow. (Ber.)
• Cuba yellow. (C.) and (W. Bros.)
• Indian yellow. G. (C.)
• Chrysoine ext. (W. Bros.)
• Azo-flavine. (B.S. Spl.)
• Turmeric yellow B. (Leitch.)
• Azo-yellow FY. (R.H. & S.)
• Orange 4. (R.H. & S.)
• Naphtol yellow S. (B.A.S.F.)
• Turmeric yellow Y. (Leitch.)
• Azo-flavine 7032. (S.C. Ind.)
• Turmeric yellow. (G.)
• Solid yellow Y. (Leon.)
• Solid yellow B. (Leon.)
• Milling brown G. (Leon.)
• Napthamine yellow 3 G. (K.)
• Orange GG. (C.)
• Resorcin yellow. (Ber.)

Greens.

• Acid green conc. (M.L.B.)
• Acid green ooo. (Leon.)
• Guinea greens G and B. (Ber.)
• Acid green ext. conc. (C.)
• Fast acid green BN. (C.).
• Erioglaucine. (G.)
• Acid green 5677. (W. Bros.)
• Acid green (Uer.)
• Light green SF. (B.A.S.F.)
• Acid green ext. GG. (By.)

Violets and Blues.

• Bavarian blue DB. (Ber.)
• Blue R. (Lev.)
• Water blue TR. (B.A.S.F.)
• Fast blue O. (M.L.B.)
• Water blue 4B. (Leon.)
• Cyanole extra. (C.)
• Acid blue. (C.A.)
• Acid violets 3BN and 6BN. (Lev.)

Oranges.

• Orange 2, (S.C. Ind.); C, (M.L.B.); B, (By.) and (B.A.S.F.).
• Orange A. (Leon.)
• Orange G. (R.H. & S.)
• Ponceaus. (Ber.) and (By.)
• Crocein oranges. (K.) and (By.)
• Mandarine G ext. (Ber.)
• Atlas oranges. (B.S. Spl.)

Scarlets and Reds.

Most acid scarlets and reds dye chrome leather well on the mordant, particulars of which are given above.

Blacks.

These are dyed direct without any mordanting.

• Leather black V. (By.)
• Leather black 1. (S.C.Ind.)
• Naphthylamine blacks 4B and 6B. (C.)
• French black. (Uer.)
• Chrome leather black. (C. & R.)
• Coomassie black 4BS. (Lev.)
• Phenylamine black 4B. (By.)

Titanium salts (potassium titanium oxalate and tanno-titanium oxalate) may be employed in conjunction with the coal-tar colours for dyeing chrome leather, with many advantages over the ordinary mordants, the colour produced being faster to light, rubbing, fuller in shade, and with much less tendency to “grinning.” When employing titanium mordants, the leather should be first lightly mordanted with some tannin solution and afterwards dyed with the titanium and dye-stuff in the same bath, in which case only “acid” dyestuffs may be employed. If desired the goods may be mordanted with the tannin mordant, afterwards treated with the titanium salts, washed and dyed; in this case the dyeing and application of the titanium mordant being carried out separately, the leather may be dyed with either the acid or basic dye stuffs. The titanium and tannin mordants may also be applied in the same bath.

Dyeing Chamois Leather.

The following colours dye chamois leather well, after washing the leather in a weak soda solution, mordanting with 3 per cent. basic chrome alum solution, and transferring to the dye-bath without washing. Equal weight of bisulphate of soda to that of the dyestuff is added to the dye-bath.

Basic Coal-Tar Colours.

• Bismark brown extra. (Ber.)
• Philadelphia yellow R. (Ber.)
• Pure phosphine. (C.)
• Leather blue V. (G.)
• Leather brown Y. (S.C. Ind.)
• Leather brown A. (S.C. Ind.)
• Philadelphia brown. (Ber.)

Acid Coal-tar Colours.

• Circumine extra. (Ber.)
• Resorcin brown. (Ber.)
• Induline NN. (B.A.S.F.)
• Orange 2. (M.L.B.)
• Golden brown. (Leitch.)
• Fast brown. (By.)
• Azo-yellow R. (M.L.B.)
• Napthylamine black 4B. (C.)
• Chocolate. (Uer.)
• Azo-flavine RS. (C.)
• Azo-phosphine. (Uer.)
• Acid anthracene brown R. (By.)
• Acid green conc. (M.L.B.)
• Acid brown Y. (S.C. Ind.)
• Acid brown B. (S.C. Ind.)
• Napthylamine black 4B. (O.)
• Jet black cryst. (C.)
• Anthracene brown R. (By.)
• Anthracene brown GG. (By.)
• Anthracene brown W. (By.)
• Dark nut brown. (Uer.)
• Orange 2. (M.L.B.)

Natural Dyestuffs.

• Peachwood extract.
• Sapan ext.
• Logwood ext.
• Fustic ext.
• Turmeric ext.

A variety of shades may be obtained on chamois leather by mordanting in a 1 per cent. solution of the titanium salts above mentioned and then transferring without washing to the dye-liquor, which is best used in the drum. The colours which are most suitable are the Alizarin colours, Janus colours and the natural dyestuffs.

Alizarin Colours.

Alizarin black	produces	light slate.
Alizarin orange	„	bright orange.
Alizarin blue	„	blue.
Azo-alizarin black	„	brownish maroon.
Azo-alizarin brown	„	reddish violet.
Alizarin red	„	bright scarlet red.
Azo-alizarin blue	„	slate blue.
Coerulein	„	yellowish green.
Azo-alizarin yellow	„	bright yellow.
Anthracene brown	„	fawn brown.
Acid anthracene brown G	„	brownish orange.
Acid anthracene brown R	„	dull chocolate brown.
Anthracene blue	„	pale blue.
Mordant yellow	„	lemon yellow.

Janus Colours.

Janus yellow G.	produces	bright orange.
Janus yellow R.	„	reddish orange.
Janus red	„	dark maroon.
Janus claret red	„	bluish maroon.
Janus brown R.	„	dark reddish chocolate.
Janus blue B.	„	bluish black.

Natural Dyestuffs.

Barwood	produces	salmon pink.
Logwood	„	dull reddish brown.
Fustic	„	bright yellow.
Turmeric	„	yellow.
Brazil wood	„	reddish brown.
Sapan wood	„	light nut brown.
Sumach	„	buff yellow.
Persian berries	„	light orange yellow.
Madder	„	red.
Quercitron bark	„	light orange yellow.
Cutch	„	fawn brown.
Campeche	„	canary yellow.
Peach wood	„	pale reddish tint.
Divi-Divi	„	buff yellow.

The leather is run in the dyestuff solution at a temperature of about 45° to 50° C. for about half an hour, and then lightly fat-liquored, if desired, and afterwards dried.

In addition to the dyestuffs mentioned above many basic colours may be employed after the treatment with titanium, some of these producing a colour lake with the titanium mordants.

As regards the permanency of the various colours to light, the reader is referred to an important paper by Mr. Lamb,[199] but in many cases the probable permanency is indicated by a number prefixed to the name of the colour in Roman figures, I. corresponding to the lowest, and X. to the highest permanency. In the research referred to, about 1500 samples of leathers dyed with coal-tar dyes were exposed to light for a series of “periods,” each equal in actinic power to nine days of the brightest summer sunshine. The most fugitive colours faded completely, even in the first “period,” and the most permanent before the end of the tenth. The prefixed numerals indicate to which of these “periods” the colour survived.

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