2 \6 ON THE QUANTITY OF CARBON IN CARBONIC ACID. 



in which the salt of Mr. Deschamps does not exist, since 

 it is insoluble in such menstruunis, cure intermittent fe- 

 vers. 



Besides, there are cinchonas, which contain but extremely 

 small quantities of this salt, and vegetables in which none 

 of it is found, that likewise cure fevers. Tt is not then 

 without reason, as is obvious, that I express my doubts on 

 this head: and if it have sometimes happened, that this salt 

 has cured fever, we may suspect, that it had not been perfectly 

 freed from the bitter principle, which it strongly retains. 

 Desirable that It is desirable however, that this question should be re- 

 b S J l()U ( j d be solved by experiment as soon as possible: for, if the results 

 of experience be conformable to those of the physicians of 

 Lyons, it would certainly be a very useful discovery for man- 

 kind. 



VIII. 



On the Quantity of Carbon in Carbonic Acid, and on the 

 Nature of the Diamond, By William Allen, Esq. 

 F.L.S. and William Hasledine Pepys, Esq. Com- 

 municated by Humphry Davy, Esq., Secretary R. S. 

 M. R. I. A* 



Quantity of JL HE estimates of the quantity of real carbon in carbo- 



carbonmcar- b on j c ac jd differing very widely, and the experiments of 



bonic acid not _ _ __ & , * , • c . v i 



ascertained Guytpn de Morveau upon the combustion or the diamond, 



and experi- detailed in the 3 1st volume of the Annales de Chbnie, being 

 ments on the .... , . n ,, • , . , .,, 



diamond ob- liable to some objections, from the manner in which the 



jectionable. operations were conducted ; we determined to institute a 

 set of experiments, in order, if possible, to settle the ques- 

 tion. 



Lavoisier, from the result of experiments apparently con- 

 ducted with much accuracy, concluded, that every hundred 

 parts by weight of carbonic acid consisted of 28 carbon and 

 72 oxigen. This was in a, great degree confirmed by the 



♦ Philos. Trans, for 1^07, Part II, p. 267. 



very 



