T. 8. Hunt on the Theory of Types in Chemistry. 257 
cies. Starting from the fact that all the carbon compounds found 
in the vegetable kingdom are derived from carbonic acid with 
the concurrence of water, he proceeds to show how all the bod- 
ies of the carbon series may be deduced from an oxyd of carbon, 
which is either carbonic acid, carbonic oxyd, or the hypothetical 
the replacement of a second Sef would yield C,0,H,, 
thy], C,H,, for one or more atoms of hydrogen in the preceding 
glycerin 
like citric from a triple molecule, C,0,, @ moreover com- 
pares sulphuric acid to carbonic acid and deduces from it by sub- 
stitution the various sulphuric organic com s. Ammonia, 
PbE 
PbO, , and BiO,. 
Ad. Wurtz, in the Repertoire de Chimie Pure for October, 1860, 
has given an analysis of Kolbe’s memoir (to which, not ohio 
the original before me, I am indebted for the Lat sketch), and 
€ 4 
bon, sulphur, and the metals, Wurtz would maintain but three, 
pis rogen (H,), water (H,O,), and ammonia (NH,), and these 
three types, as i 
_* See on this subject Dr. Frankland’s late excellent lecture on Organo-metallic 
bodies in the Quarterly Journal of the Chemical Society, July, 1860, Nos. L, LI. 
