588 DR MACVICAR ON THE LAW OF VOLUMES OF AERIFORMS 



to give five elementary tj^pes, all different from each other, and the compounds 

 may be numberless. The first molecule is the tetrahedral (CjH^)^ = C^oH^g. This, 

 with half a normal or aqueous volume, or the octohedral molecule with one 

 such volume, or the icosatom with two, gives,— 



Essential Oils G = ; 



But when, in order to continued existence, greater stability is required (as in 

 drenching with chlorhydric acid) the dodecatom in some cases is constructed. 

 Thus, of cubeb camphor, the formula is Cj5Hj^2ClH=(C5H^)3ClH, a very usual 

 formula. When expanded, it gives type rj (p. 583). And calling C^H^^X, and 

 C1H = Y we obtain,— 



YXY (X),„YXY. = X,,Y, or X,Y, or X3Y. 



Camphor G = { ^&f^ = '''\ll''' = '^^- Expt. -99. 



Sugar G = ( &?^^= 12 x (72 + 11 + 88) ^^.^3 ^.^^ _ _ ^.^ 



* t 4AQ 4 X 324 ^ 



(iC,H^OJ^_60x^^_ 

 4AQ 4 X 324 



Acetic Acid G = 



= •926. 



I Mean 1-068. Expt. 1063 . . 1-065. Liquid. 

 (^&^Jh,^^A^\ = l.ni. Expt.M. Solid. 



2AQ 2 X 324 



This implies that the melted crystals of acetic acid consist of dodecatoms and 

 icosatoms in equal numbers— a complete differentiation, which also appears in 



fCAIiMo _46x20|_ 

 4AQ ~4x324 j 



Alcohol G = ) Mean -796. Expt. -795. 



_(C^H,0^,_46xl2| .332 

 Iv 2AQ 2 X 324 1 



Ether is an eminently mobile liquid, and, when alone, seems to be constructed 

 like the essential oils. 



Ether G = 



iAQ ~ 162 • • 



Mean -742. Expt. 736. 



(C^H,0)^„_ 37x20^ 



4AQ ~4x324 



Metals. 



We may here take the leading metals in the order of the simplicity of their 

 molecules. 



