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an important form of animal charcoal, is obtained. Another form 

 is prepared by charring dried blood. Bone black contains a large 

 proportion of earthy salts, chiefly phosphate of lime. When these 

 have been removed by the action of acidulated water the washed 

 and dried product is the animal charcoal so useful in removing 

 colouring matters from organic compounds. Bone and blood 

 charcoals are largely employed in sugar refining and bone black 

 is also used in the preparation of black pigments. 



Coke is related to coal in the same way that charcoal is 

 related to wood. It is obtained as a secondary product in the pre- 

 paration of coal-gas and is the principal or primary product of the 

 coke-oven. It contains about 92 per cent, of carbon, the re- 

 mainder consisting of the mineral matter that was present in the 

 coal from which it was made together with small amounts of 

 hydrogen, nitrogen and sulphur. It is t much used as a fuel, 

 especially in smelting operations and other cases in which a very 

 high temperature is required. When steam is brought into 

 contact with highly heated coke it yields water-gas, a mixture of 

 hydrogen and carbon monoxide. This is a valuable gaseous fuel 

 and is used by our local Gas Company for mixing with ordinary 

 coal gas. Soot is another familiar form of impure carbon, it 

 results from the imperfect combustion of coal, It is partly de- 

 posited in our chimneys and partly escapes from them with the 

 smoke, forming a constituent in that complicated mixture known 

 as fog. Soot contains an appreciable quantity of ammonia com- 

 pounds, and it is to these that its usefulness as a manure is due. 

 Lampblack is a kind of specially prepared soot, which has many 

 applications. Such combustibles as tar, resin, turpentine, and 

 petroleum are burnt with a supply of air so small as to produce 

 a flame rich in smoke. This passes into chambers where the finely 

 divided carbon is deposited in coarse cloths. For the finer kinds 

 metallic cylinders revolve over special lamps burning with very 

 smoky flames. The crude lamp-black is purified by heating it in 

 closed vessels. The imperfect combustion of the natural gas. of 

 the oil-producing districts of the United States has also been 

 largely used in making lamp-black. This form of finely divided 

 amorphous carbon is employed as a pigment, forming the bases 

 of both oil- and water-blacks. Indian or Chinese ink is made from 

 the purest and best lamp-black mixed with a solution of some 

 gummy substance. It is said that for the very finest Chinese ink 

 camphor black is used. Printers' ink also is made from, lamp-black 

 diffused through an oily or greasy medium. Resin and other 

 cheap oils serve for the commoner varieties of this ink, but the 

 better kinds are made from good lamp-black and drying oils, such 

 as linseed or poppyseed, which have been strongly heated and so 

 converted into a kind of varnish. Lithographic ink is a very 

 carefully prepared printing-ink of special quality. The ink used 

 for "blacking-out" in connection with the press censorship is 

 diluted printing-ink. 



The typewriter is a kind of cousin to the printing press and 

 is equally dependent upon carbon-containing inks. The black 



