466 Mr. Davy’s new analytical Researches 
Dr. Marcet, who is engaged in some experiments on the 
subject, and from whose skill and accuracy, further elucida- 
tions of it may be expected. 
III. Further Inquiries respecting carbonaceous Matter. 
On the idea which I have stated, page 73, that the diamond 
may consist of the carbonaceous matter combined with a little 
oxygene, I exposed charcoal intensely ignited, by Voltaic 
electricity,* to nitrogene, conceiving it possible that if this body 
was an oxide, containing oxygene very intimately combined, 
it might part with it in small proportions to carbonaceous 
matter, and give an important result. 
The charcoal, which had been made with great care, was 
preserved for a quarter of an hour in a state of ignition, in 
which platina instantly fused. It did not appear to change in 
its visible properties ; but a small quantity of black sublimate, 
which proved to be nothing more than finely divided carbo- 
naceous matter, collected in an arborescent state upon the 
platina wire to which the charcoal was attached. The gas had 
increased in volume one sixth ; but this was owing to the evo- 
lution of carburetted inflammable gas from the charcoal, the 
nitrogene was unchanged in quantity, and far as my exami- 
nation could go, in quality. The points of the charcoal where 
the heat had been intense, were rather harder than before the 
experiment. 
I have mentioned, page 102, that charcoal, even when 
strongly ignited, is incapable of decomposing corrosive sub- 
limate. When charcoal, in a state of ignition, is brought in 
* The apparatus was the same as that referred to page 59. The power employed 
was that of the battery of 500 belonging to the Royal Institution. 
