Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/32

h] IN It or green vitriol; a quarter of an ounce of gum-arabic, and a similar quantity of wliite sugar. As soon as a perfect solution of these sub- stances has taken place, one ounce and a quarter of indigo finely pul- verized is to be added; together with three quarters of an ounce of the purest lamp-black, previously diluted in one ounce of the best brandy. The whole is to be well incorporated; and, after it has sub- sided, M. AVestrumb asserts that it will form an ink nl'solulelij inde- striiStible by acids. A more simple composition, is that proposed by M. Bosse, who diretts one ounce of Brazil-wood to be boiled in twelve ounces of wa- ter with half an ounce of alum, till the liquid be reduced to eight ounces; when one • ounce of cal- cined manganese is to be mixed with half an ounce of gu!n-arabic, and added (o the liquor, which should be previously decanted, in order to render it pcrfe6tly limpid. This preparation is said to possess the property of being indelible by the use of any kind of acid, and to be superior to that proposed by M. Westrumb. • A durable ink may also be pre- pared by washing paper, jjarch- ment, &c. with the Prussic acid, which will not in the least iniure cither of these substances. The materials, thus prepared, may be written on with common ink, and a ground of Prussian blue will be formed beneath every stroke, whiL-h will remain long after the black has decayed by the intluencc of the air, or bc'.^n destroyed by acids. Tiie latest, and perhaps most simple, preparation of black ink, is that contrived by Van Mons, who observed that sulphate of iron, or green vitriol^ when calcined till it 11^ Z became tvhile, uniformly afForaed a very beautiful black precipitate. According to his experiments, the' follov/ing ingredients produced ait excellent writing ink : four ounces of galls, two ounces and a half of calcined vitriol of iron perfeftly white, and two pints of water. The whole was infused in a cold place for twenty-four hours ; add- ing ten drams of pulverized gum- arabic, and preserving it in a glass bottle, or glazed earthen vessel,- slightly covered with paper. Indian Ink, a valuable black for water-colours, imported from China, and other parts of the East' Indies, generally in oblong squ~re cakes, impressed with Chinese cha- ratifers. The preparation of Indian ink was discovered by Dr. Lewis, according to whom it consists of lamp-black and animal glue. In order to imitate it, he dn-e6ts as much lamp-black to be mixed with the glue, as will be sutficient ta give it a proper tenacity lor making it into cakes. This composition is said fully to answer the ditferent purposes to which the genuine In- dian ink is subservient, both with regard to the colour, and the faci- lity with which it may be applied. Dr. Lewis farther found that ivory- black, and other blacks obtained from charcoal finely levigated, may be advantageously substituted for lamp-black : ivory and charcoal,- however, are generally sold in so gross a state, as to prove gritty when worked, and to separate tuo spee- dily from the water. Ink-powder is prepared chiefly from the acid salt of galls, which may be obtained by the following process : Take two ounces of pul- verized galls, and infuse them in twelve ounces of rain or river-wa- ter J expose the whole for a few days