10 



REPORT 1859. 



6. The addition of two atoms of oxygen to acetic acid produces a homo- 

 logue of glyceric acid, containing C 2 H 4 4 *. We are justified by analogy in 

 assuming that in this compound three out of the four atoms of hydrogen are 

 separable from the carbon. The possible production of such a compound is 

 indicated by the formula 



H 



\in 



3 }(CH)' 

 ( C) iv \ \0 derived from 



H>0 



7. The last formula expresses every possible decomposition of acetic acid 

 except the complete separation of its carbon and hydrogen, which occurs 

 when \ of the latter is replaced by a metal and the remaining -| by chlorine, 

 as in a metallic terchloracetate, or when acetic acid is completely oxidized 

 into carbonic anhydride and water. To express such reactions as these, in 

 connexion with those already considered, acetic acid must be represented as 

 built up of separate elementary atoms, without the subordinate combination 

 of even two of them into a compound radicle. For in the reactions which 

 have been enumerated, all the atoms of which acetic acid is composed, are 

 one by one separated from each other; so that not one of them remains 

 combined directly or indirectly with any of the rest. Hence the formula at 

 which we finally arrive, the most general that it is possible to give, is the 

 following : — 



derived from 



H 



(C)-{}(°)" 



i}(o)" 



or one of equivalent meaning. 



In this formula all the atoms are represented as entering into combination 

 on an equal footing, and each in turn may be regarded as a radicle or part 

 of the type. 



Before leaving the subject, it is worth while to point out that each set of 

 relations which we have successively considered, in order to generalize more 

 and more the formula of acetic acid, has in its turn been made the founda- 

 tion of a separate rational formula. 



Upon the binary theory of acids, acetic acid receives the formula C 2 H 3 

 2 .H, which is the same in form and meaning as that given in (1). The 

 formula given by Williamson and Gerhardt (2) was intended to express the 

 relation of acetic acid to chloride of acetyl, acetamide, &c. Liebig's for- 



* Perkin and Duppa, Chem. Soc. Quart. Journ. xii. 6. 



