22 Prof. H. Rose on the Inorganic Constituents 



When the gas was })assed through too slowly, combustion diil 

 not take place; but as soon as it was allowed to flow. more 

 quickly, t!ie oxidation of the carbon occurred with the pro- 

 duction of a vivid light, and white fumes were distinctly seen 

 to ascend. For the purpose of examining the volatilized pro- 

 ducts, the combustion of the carbonized mass was effected in 

 a tubulated glass retort, through the tubulure of which the 

 oxygen was passed, whilst its mouth was inm)ersed in water. 

 The water was found to exhibit powerful reactions of phos- 

 phoric acid and alkali. 



If a mixture of alkaline phosphate with a large proportion 

 of carbon is artificially prepared, and the mixture burnt in a 

 current of oxygen, the same phsenomena as those just described 

 are found to occur, and dense white fumes are seen to ascend. 



This volatilization only occurs with alkaline phosphates. 

 On the combustion of a carbonized substance, which after in- 

 cineration yields earthy phosphates only, volatilization cannot 

 be perceived. Moreover, when earthy phosphates are artifi- 

 cially mixed with carbon, and the mixture burnt in oxygen 

 gas, volatilization does not occur, nor can any white fume be 

 perceived. Hence the earlier experiments which were per- 

 formed in my laboratory, in which the washed carbonized 

 mass was burnt in oxygen gas, have yielded incorrect results, 

 and must therefore be repeated, as a method has at last 

 fortunately been discovered by which the combustion can be 

 effected without loss. This method, which was proposed by 

 M. Fleitmann, is as follows : — 



The carbonaceous mass, after having been exhausted with 

 water and muriatic acid, is dried, and then moistened with a 

 concentrated solution of chloride of platinum. The moist 

 mass is heated in a porcelain crucible or a porcelain capsule, 

 at first gently, so that no moisture may be expelled and no loss 

 occasioned by the spirting of the mass ; then more strongly, 

 so that it attains an incipient red heat. This is best effected 

 in a large concave lid ot a platinum crucible. If the whole be 

 heated in a porcelain crucible, the incineration requires a far 

 longer time, inasmuch as it takes place more slowly in pro- 

 portion to the smallness of the surface and the less free con- 

 tact of the air. A very slow combustion of the carbon ensues, 

 chlorine being simultaneously developed ; each carbonaceous 

 particle becomes incandescent, just as in the scintillation of an 

 inflamed vegetable substance. The combustion is extraordi- 

 narily increased by constantly stirring the mass with a plati- 

 num wire or a small platinum spatula. As fresh portions of 

 the unburnt carbon come into contact with the air, the scin- 

 tillation recommences. The spirit-lamp may be removed, 



