460 THEORY OF TYPES IN "CHEMISTRY. [XX. 



in the former we replace one atom of oxygen by one 

 of hydrogen we have C 2 3 H, or anhydrous formic acid ; the 

 replacement of a second equivalent would yield C 2 2 H 2 , or 

 the unknown formic aldehyde ; a third, C 2 OH 3 , the oxide of 

 methyle ; and a fourth, C 2 H 4 , or formene. By substituting 

 methyle for one or more atoms of hydrogen in the previous 

 formula, we obtain those of the corresponding bodies of the 

 vinic series, and it will be readily seen that by introducing the 

 higher alcoholic radicles we may derive from C 2 4 the formulas 

 of all the alcoholic series. A grave objection to this view is, 

 however, found in the fact that while this compound may be 

 made the type of the aldehydes, acetones, and hydrocarbons, it 

 becomes necessary to assume the hypothetical C 2 2 ,HO, as the 

 type of the acids and alcohols. Oxide of carbon, C 2 2 , is, 

 according to Kolbe, to be received as the type of hydrocarbons 

 like olefiant gas (C 2 HMe), while C 2 0, in which ethyle replaces 

 oxygen, is C fl H to or lipyle, the supposed triatomic base of 

 glycerine. 



The monobasic organic acids are thus derived from one atom 

 of C-jO^ while the bibasic acids, like the succinic, are by 

 Kolbe deduced from a double molecule, C 4 8 , and tribasic 

 acids, like the citric, from a triple molecule, CeO^. He more- 

 over compares sulphuric acid to carbonic acid, and derives from 

 it by substitution the various sulphuric organic compounds. 

 Ammonia, arseniuretted and phosphuretted hydrogen, are re- 

 garded as so many types ; and by an extension of his view of 

 the replacement of oxygen by electro-positive groups, the 

 ethylides, ZnEt, PbEt* and BiEt s , are, by Kolbe, assimilated 

 to the oxides, ZnO, Pb0 2 , and Bi0 3 . 



Ad. \Vurtz, in the Repertoire de Chimie Pure for October, 

 1860, has given an analysis of Kolbe's memoir (to which, not 

 having the original before me, I am indebted for the preen ling 

 sketch), and follows it by a judicious criticism. While Kolbe 

 adopts as types a number of mineral species, including, the 

 oxides of carbon, of sulphur, and the metals, Wurtz would 

 maintain but three, hydrogen (H 2 ), water (H 2 2 ), and ammonia 

 ( N 1 1 3 ) ; and these three types, as he endeavored to show in 



