182 Experiments made at the Polytechnic Schoos 
oxygen gas, in the ratio of 1°3577 milligrammes cach, pro- 
duced, with the 1999 milligrammes of the dianiond, ¥117°96 
milligrammes of carbonic ate: 
Int the laft place; that, inftead of the proportions 0°28 of 
combuttible fubftance, and 0°72 of acidifying principle, ob- 
ferved in the combuftion of sani the proportion was, for 
the combutftion of the diamond, - 17°88 of carbon. 
82°12 of oxygen. 
100°090 
Though it was not poffible for me to doubt faéts deduced 
from calculation, I at firft hefitated to admit differences fo 
confiderable in the manner in which the fame combuftible 
united itfelf to oxygen in the quantities it could take up, and 
the products of its combuftion; in a word, a carbonaceous 
eombuftible more abundant in real combuftible matter than 
charcoal itfelf, and which at the fame time differed fo much 
from it m the degree of temperature neceflary to determine 
the action of its affinity. But I foon began to refleét, 1ft, 
Fhat this would not be the only inftance of the firft degree of 
the oxydation of an acidifiable bafe having been operated with 
great difficulty, while the acidification was afterwards com- 
pleted with the utmoft facility: 2d, That feveral fubftances 
of the fame kind prefented to us gio thefe two characters ; 
a greater abundance in real earbon, and greater refiftance to 
namin ation» ; fo that they naturally placed themfelves in an 
imtermediary rank between the diamond and charcoak. Thefe 
two confiderations, {lill ftrengthened by the fimilarity of the 
phenomena obferved during dig courfe of cur two experi- 
ments in the paflage of the diamond to the {tate of earbonie 
acid, appeared to me to throw a ray of Jight on this fubjec& 
hitherto fo obfeure. 
In regard to the firf confideration it will be fufficient for 
me to call to mind with what difficulty the commencement 
ef a compofition of azot and oxygen is formed by the, direc 
way, and the high degree of temperature which it requires, 
while nitrous gas cannot be in contact with oxygen without 
palling immediately to the acid ftate. Charcoal will then be 
to the carbonic acid what nitrous gas is to the nitric, and ” 
tha 
