240 LAYOISIER. 



The production of fixed air by burning charcoal, alcohol, 

 ether, in close vessels had been long known; but M. 

 Lavoisier carefully subjected charcoal to the same process 

 which he had made the diamond undergo, and the result 

 was nearly the same. 



The conclusion at which he arrived from these experi- 

 ments, is marked by a caution truly philosophic, and as 

 well deserving our admiration, as the sagacity which 

 distinguished the conduct of the inquiry. " We should 

 never have expected," he says, " to find any relation 

 between charcoal and diamond, and it would be unreason- 

 able to push this analogy too far; it only exists because 

 both substances seem to be properly ranged in the class 

 of combustible bodies, and because they are of all these 

 bodies the most fixed when kept from the contact of air." 

 He adds, "It is far from being impossible that the 

 blackish matter should come from surrounding bodies, 

 and not from the diamond itself." 

 - It is needless to remark how very near he was, in 

 this inquiry, to making the discovery that diamond and 

 the pure carbonaceous matter are identical, and that both 

 form y alike 5 fixed air by their union with another and a 

 gaseous substance. Dr. Black had shown, nearly twenty 

 years before, that fixed air was the product of the com- 

 bustion of charcoal. Had M. Lavoisier performed his 

 experiments on that combustion with a little more care, 

 he would have made the discovery in 1773, which he did 

 a few years later; and as he then was occupied in con- 

 sidering the nature of the diamond, its identity with 

 carbon would not have escaped him as it afterwards did 

 when he first ascertained the composition of fixed air. 



In 1773, M. Lavoisier made some very accurate expe- 



