586 DR MACVICAR ON THE LAW OF VOLUMES OF AERIFORMS 



Carhon. 



Like phosphorus carbon is an eminently allotropic substance, giving specially 

 these three forms (independently of those which are proper to organisation and 

 charcoal, which I shall not touch upon) ; first, the diamond ; secondly, an in- 

 combustible or less combustible residuum when diamond is burned ; and, thirdly, 

 coke and graphite. According to what has been stated, the diamond being a 

 mature product of nature, eminently stable, ought to have for its molecule a 

 structure differentiating itself, such as 0^2^.,^ or Cg^- The more combustible part 

 ought to be the open or circumscribing icosatom, C.,,,, leaving Cj^ as the residuum. 

 The icosatom ought also to be the molecule of coke and perhaps graphite. 



Diamond . Q = ^A^ = ^^2lJl±}^ = ^.^Q, Expt. 3-55. 



2AQ 648 ^ 



Unburnt Residuum G =^%o^= ^^|^^ = 2-67. Expt. 2 6? (Jacquelain.) 



Coke . . Qj^^n=}l^J^=,2-22. Expt. 1-8 .. . 2-3. 

 2AQ 648 ^ 



LiEBiG has proposed as the formula of Newcastle coal Co^H^gO. This is 

 obviously a dodecatom of CHC = C^H, moistened all over by an atom of HO on 

 each of the twelve points of the periphery. It is a good molecular formula; 

 but coal is not an individualised substance. Detach the moisture, however, to 

 obtain a pure hydrocarbon, and then impart to it stability in the current of che- 

 mical action by bestowing an atom of oxygen gas, — i.e., 20, on each pole, or 

 merely when — 16, and we obtain two of the most eminent products of the dis- 

 tillation of coal, our formulae being as usual the doubles of those usually given. 



Benzene -^gp = ^Z, = "963. Expt. -956 (solid.) 



^ , ,. ., C„,H,„0, 144-F124-32 , ,. t> . i ne^ 

 Carbolic acid - ^* /A - = ^ao = 1 " 1 6 . Expt. 1-065. 



But these calculations are on the supposition that the entire mass or liquid 

 consists of homogeneously constructed molecules, of which there is but little chance. 



By simple additions of its own elements, CHC = C2H, instead of oxygens on the 

 poles, Benzene gives Toluole, &c., . . . Cymole. And it dedoubles into naphtha 

 (CH)^2 = 0^2 H121 or with H omitted on the poles, 012^10- 



The element CH being the same in all, and the liquid differentiated to the full, 



there may be, — / 



(CH),o_140_ 

 -i-AQ ~ 162 " 



Naphtha G = ( ^^^%^2»^^^Ky^= '69 ) Mean -86. Expt. -86 . . . -90. 



(CH),2_84^ 

 ^iAQ -80 



