CARBON. 33 



that of carbonic oxide 0.96779, Comparison gives C = 

 75.11 to 75.14. (Berzetius' Jahrcsbericht, £?, 1842, 72.) Berze- 

 lius adopted this determination. 



Accordino; to Graelin-Kraut, 1, (2,) 70, Regnault's value 

 for the specific gravity of oxygen combined with von Wrede's 

 for carbon di-oxide gives C = 12.0037, and with that for car- 

 bonic oxide C= 12.0105. 



J. S. Stas : 13.005 (O = 16) ; 75.030 (0 = 100). 



Determined by passing carbonic oxide over a known 

 weight of pure cupric oxide, and weighing the carbon di- 

 oxide formed. Stas got from eight experiments C = 74.993 

 to 75.055. [The number taken is the mean of the results, 

 which is misprinted in Stas' paper 75.039.] The carbonic 

 oxide was prepared from oxalic acid by the action of sul- 

 phuric acid. It was purified from carbon di-oxide by pass- 

 ing through potash tubes, and from oxygen by passing over 

 hot copper filings, and was kept in a gasometer over water, 

 in which was dissolved a solution of stannous oxide in pot- 

 ash. The cupric oxide was prepared by igniting pure cupric 

 nitrate. The carbonic acid formed in the experiments was 

 caught in potash and sulphuric acid tubes. The amount of 

 carbon di-oxide weighed was from 23 to 67 grammes. The 

 weighings are reduced to vacuum. {Bulletin de VAcad. Roy. 

 des Sciences de Belgique, 16, 1849, 9.) 



GRAPHON. 



B. C. Brodie : 33 (0 = 16). 



By the action of potassic chlorate and nitric acid on gra- 

 phite, Brodie obtained a compound of carbon, oxygen and 

 h^'drogen containing 11 atoms of carbon, and by the action 

 of heat on this substance two others containing, respectively, 

 22 and 66 atoms. The first of these is analogous to the 

 hydrated oxide of silicon obtained by Buft' and Woehler, 

 if Si = 21. From this fact, and the specific heat of gra- 

 phite, Brodie concludes that the atomic weight of the 

 graphitic form of C is 33. {Phil. Trans., 1^9, 1859, 249.) 

 Graham-Otto points out that if Si = 28, graphon must be 

 44, and that, in that case, the argument from the specific 

 heat loses its applicability. 



