French Nat'mial Injliiuie. 8^ 



and moa untraaable of ftones is converted into a little fmoW 

 and foot. But the queftion was, What is the nature of th« 

 combuftibie body ? Is it a particular fpccies, like fulphur, or 

 phofphorus ? or is it a compound of different combulhble 

 bodies, as oils and bitumens ? There was only one way of 

 anfwerinc thefc queftions— to colka the produa of its com- 

 bulUon. "^ This has been done, and the produa was found to 

 be abfolutely the fame as that of the combuftion of charcoal j 

 that is to fay, that deleterious vapour to which chemifts have 

 given the name of carbonic acid gas. Are the diamond and 

 charcoal then the fame thing ? or, if not, in what do they 

 differ ? This is the problem which C. Guyton prop.^fcd, and 

 which he has refolved. lie firft faw the diamond change it- 

 felf into carbonic acid without leaving a rcfiduum : if it differs 

 then from charcoal, it is only becaufe it contains fumethmg 

 more. It produces much more of that acid, becaufe it ab- 

 forbs more oxvgen during combuftion than charcoal does; 

 and if the combulVion be fufpended at a certain point, which 

 C. Guyton did, by burning the diamond by means of the 

 folar rays, vou obtain real carbon. Thus common char- 

 coal, making allowance for the earthy and faline mallei's 

 which form °he aflies, is not a fimple fubftance, as hilherto 

 believed. The diamond, by its firft combination with oxy- 

 gen, is converted into that fubftance of which the Englilh 

 make pencils, and which is called plumbago; by a fecond 

 degree, into common black charcoal ; and by complete hXn~ 

 ration, into carbonic acid. The diamond, then, is really thai 

 ideal and fimple being which chemifts called carbon, and 

 common charcoal is only carbon more oNvgenated ; that u 

 to fay, the two fubftanccs, which in iheir nlual ftale appear to 

 us the moft tranfparent, form, by their union, the blackcft 

 and moft opaciue of fubftances, and one of the connnoncft 

 of fubftances contains a great part of its weight of that which 

 wc confider as the moft valuable. 



But C. Guyton has done more. It is well known that 

 iron is converted into fteel by ctmibining itfelf with a certain 

 ciaamity of carbon. C. Guyton was defirous of afccrtaining 

 in what ftale carbon entered into this combination, and, 

 Hbove all, whether it abandons its oxygen to form ftce; : 



C. Guyton 



