ON THE QUANTITY OF CARBON TN CARBONIC ACID* £35 



matter, &c. we shall endeavour to estimate the carbon by 

 the experiment on plumbago. When 13*35 grains of car- 

 bonic acid contained 3*80 grains of carbon, 



13-35:3-80 :: 9*49: 270. 

 The quantity of carbonic acid produced in this experiment, Containing 2*7 

 therefore, contained 2*70 grains of carbon. fir3 of carbon * 



Loss 3*20 



Carbon 270 



Leaves *50 for volatile saline matter, &c. 



So that, this being granted, the present experiment agrees Matter volati- 

 with the foregoing. lizeel/ * 5 S rs ' 



In two of our first experiments with box-wood charcoal, j n some eX pe. 

 the calculations gave us in one case 2975 parts of carbon in fiments quan- 

 100 of carbonic acid, and the other 30*68; but we were apparently ^ 

 not then fully aware of the absorption of water by charcoal, greater. 

 which rendered the quantity of real carbon employed less 

 than indicated by the weight. Also in another experiment, 

 in which 4 grains of diamond were consumed, the calcula- 

 tion gave us 29*06 per cent of diamond in carbonic acid ; 

 but apprehending, that a slight degree of inaccuracy had 

 crept into this experiment, we have not detailed it with the 

 rest ; but we have thought it right to give a simple statement 

 of matters of fact; in no one instance have we endeavoured 

 to strain or accommodate these to suit any particular theory, 

 being fully aware, that every experiment, carefully made and 

 faithfully recorded, will remain an immutable truth to the 

 end of time, while hypotheses are constantly varying, and 

 even the most beautiful theories are liable to change. 



The experiments above related give us the following results. 



. By carbonic acid. By oxigen. 



Box-wood charcoal • • 23 92 

 lstexpt. diamond ■ . . . 28*95 

 'id expt. diamond • • . • 28*82 



Stone dotal 28*20 



Plumbago ,. . 28*46 



>) 143*35 * 5)143*03 



mean 2S*67 28*60 



Hence, 



