"Instead of acting upon anthracen by means of sulphuric acid of the density before mentioned, fuming sulphuric acid may be employed, but we prefer to use the ordinary kind before described.
"In order to effect the process of oxidation, before referred to, other oxidising agents may be used in the place of the oxide of manganese, before mentioned, such, for example, as perioxide of lead, or chromic, nitric, or other acids capable of effecting the desired oxidation may be employed."
Mr W. H. Perkin's patent is similar in principle to that of Messrs Caro, Graebe, and Liebermann, and is dated only one day later.
The following is an outline of a patent taken out in France in May, 1869, by MM. Brnner and Gutzkon, for the manufacture of artificial alizarin.
One part of anthracen is heated with two parts of nitric acid, sp. gr. 13 to 15. The anthraquinone thus produced is washed and dissolved at a moderate heat in sulphuric acid. Mercuric nitrate is now added, which converts the anthraquinone into alizarin, The mass thus formed is dissolved in an excess of alkali, which precipitates the oxide of mercury, and retains the colouring matters in solution. The alkaline liquor is decanted and neutralised with sulphuric acid, and the precipitate thus formed is washed and collected. If not quite pure the treatment with alkali must be repeated. (The complete specification of this patent is published in the 'Moniteur Scientifique,' vol. xi, p. 865.)
In England a large quantity of artificial alizarin is manufactured by the process of Mr Perkin, and is used as a substitute for madder and madder extract, in Turkey red dyeing and topical styles. The largest makers of artificial alizarin on the continent are Messrs Gessert Freres, of Ebelfort, Messrs Maister, Lucius and Co., of Haechst, near Frankfort, and the Badische Anilin und Soda Fabric, Mannheim.
The following recipes for printing with artificial alizarin are extracted from Mr Crookes' 'Practical Handbook of Dyeing and Calico Printing':
REDS.
5 lbs. alizarin paste (10 per cent.); 16 lbs. thickening; 1 lb. acetate of alumina, at 15 Tw.; 1/2 lb. acetate of lime, at 25 Tw.
PINKS.
The above diluted with 2 or 3 parts of thickening.
For double printing, when deep red is printed on first, the goods must be steamed one hour before the second printing takes place. After the second printing the goods are again steamed for one hour, and aged for twenty-four hours; they are then passed through one of the following baths, at from 120 to 140 F., remaining in the bath not longer than 1 to 1-1/2 minute:--
250 gals. water; 60 lbs. chalk; 3 lbs. tin crystals.
Or, 250 gals. water; 40 lbs. chalk; 10 lbs. arseniate of soda.
The goods are then washed, and cleaned as follows:--
Take, for 10 pieces of fifty yards each,--
1st. Soaping at 120 F., 3 lbs. soap; 1/4 lb. tin crystals.
2nd. Soaping at 160 F., 3 lbs. soap; 3rd. Soaping at 175 F., 3 lbs. soap.
Wash between each soaping.
RED FOR MOSAICS.
8 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 9-1/2 oz. nitrate of alumina, at 23 Tw.; 19 oz. acetate of alumina, at 15 Tw.; 13 oz. acetate of lime, at 25 Tw.
Or, 10 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 13 oz. nitrate of alumina, at 23 Tw.; 19 oz. acetate of alumina, at 15 Tw.; 16 oz. acetate of lime, at 25 Tw.
ANOTHER RED WITHOUT OIL.
8-1/2 lbs. alizarin paste (10 per cent.); 9-1/2 lbs. acetic acid, at 12 Tw.; 3-1/2 lbs. wheat flour; 5 pints water.
Boil well and stir till cold; then add--
1 lb. acetate of lime, at 29 Tw.; 2 lbs. nitrate of alumina, at 23 Tw.; 3 lbs. hyposulphite of lime, at 13 Tw.
PURPLE.
3 lbs. alizarin paste (10 per cent.); 10 quarts purple thickening; 6 oz. pyrolignite of lime, at 18 Tw.; 12 oz. acetate of lime, at 25 Tw.
The printed goods are steamed for an hour or two, and then aged from twenty-four to thirty-six hours. They are then padded in the chalk and arseniate of soda bath; after which they are washed and soaped in a single soap-bath without tin crystals; and, if needful, cleaned in a weak solution of bleaching powder.
THICKENING FOR REDS.
12 lbs. wheat starch; 40 quarts water; 4 quarts acetic acid, 9^{9} Tw.; 1-1/4 lbs. gum tragacanth; 2 lbs. olive oil.
Boil well together, and stir till cold.
THICKENING FOR PURPLE.
10 lbs. starch; 27 quarts water; 3 quarts acetic acid; 1-1/8 lbs. gum tragacanth; 2 lbs. olive oil.
Boil well together, and stir till cold.
The mordants in the above recipes are prepared as fellows:
ACETATE OF ALUMINA.
Stir 30 lbs. of hydrate of alumina into six quarts of acetic acid, warm, filter, and reduce to the specific gravity required.
The hydrate of alumina is prepared by dissolving 72 lbs. of alum in 100 gals. of water, and 62 lbs. soda in 100 gals. of water. The two solutions are mixed, this precipitate is washed eight times by decantation, collected on a filter and pressed. It must be dissolved on the filter before it gets dry.
NITRATE OF ALUMINA.
2 lbs. nitrate of lead; 2 lbs. alum; 2 quarts water.
Dissolve and filter off the liquid from the precipitate, and dilute to proper standard.
The reds are turned more yellow by nitrate than by acetate of alumina, and when the former is used more acetate of lime is taken in addition.
ACETATE OF LIME.
A solution of acetate of lime at 25 Tw. contains 25 per cent. of acetate of lime; generally 1/10th of the weight of alizarin paste is required; but with a fresh quantity of alizarin it is safer to ascertain, on a small scale, the amount needed.
BROWN.
13-1/4 lbs. alizarin paste (15 per cent.); 9 quarts thickening; 2 lbs. nitrate of alumina, at 29 Tw.; 15 oz. acetate of alumina, at 19 Tw.; 15 oz. red prussiate potash, dissolved in water; 1 lb. 1 oz. acetate of lime, at 29 Tw.
To obtain a yellower shade, for every quart of mixed colour, 1 oz. bark liquor, at 30 Tw., may be added.
Old spoiled red colours may be advantageously used for browns by adding per quart, 3/4 oz. to 1 oz. red prussiate, dissolved in water.
=ALKALI.= _Syn._ ALKALI, Fr.; LANGENSALZ, Ger. This word has been used in various senses, but is now usually applied to four substances only, viz.
the hydrates of potassium, sodium, lithium, and ammonium (the latter being supposed to exist in the aqueous solution of ammonia). In a more general sense it is applied to the hydrates of barium, strontium, and calcium, which, for the sake of distinction, are called the alkaline earths. The following properties are characteristic of the alkalies:--(1) They are soluble in water, the alkalies proper more so than the alkaline earths.
(2) They change the hue of many vegetable colouring matters; thus, they turn reddened litmus blue, yellow turmeric brown, and syrup of violets and infusion of red cabbage green. (3) They neutralise the strongest acids.
(4) They precipitate most of the heavy metals from solutions of their salts as hydrates or oxides. (5) They saponify the fixed oils and fats.
(6) They exert a caustic or corrosive action on animal and vegetable substances.