G8 MESSRS. E. PEAjS^KLAND AND B. 1\ DUPPA'S 



Thus it is evident that the replacement of each of the three atoms of methylic 

 hydrogen by the same alcohol radical is attended with a different result as regards the 

 elevation of boiling-point, and that the rise in the temperature of ebullition becomes 

 markedly less as each atom of typical hydrogen is successively replaced, although the 

 absolute thermal values of each of the three atoms depend upon functions v^^hich have 

 not yet been discovered. 



II. Constitution of the Fatty Acids. 



There is perhaps no series of organic compounds w^hich has been the subject of such 

 numerous investigations and theoretical speculations as that of the fatty acids ; never- 

 theless the synthesis of several of these acids, by a method of general application 

 described in the foregoing pages, whilst confirming some previous views regarding the 

 constitution of these bodies, has opened a path into then- basylous constituent which had 

 not previously been explored, and has disclosed the existence of vast numbers of isomers, 

 which now require only the expenditure of time and labour for their production. 



Amongst the investigations and theoretical views above alluded to, we would especially 

 call attention to those of Kolbe and Frankland*, and of Dumas f, which proved the exist- 

 ence of methyl in acetic acid, and of other alcohol radicals in the higher homologues of 

 that acid ; to Feankland's view of the constitution of the alcohol radicals themselves, a 

 short abstract of which appeared in the British Association Reports for 1855, Trans, of 

 Sect. p. 62 J ; and of Kolbe and Fkankland §, who in the year 1857 proposed the deri- 

 vation of these and a large number of other organic compounds from the carbonic acid 

 or tetratomic carbon type ; and finally, to a recent paper by Kolbe ||, in which he pre- 

 dicts the discovery of dimethacetic acid, and of other similarly constituted acids. 



"We conceive each fatty acid to be formed by the union of a chlorous and a basylous 

 radical. In all acids higher than the formic, these radicals are held together by one of 



* Memoirs and Proceedings of the Chemical Society, vol. iii. p. 386, and Ann. der Ch. und Pharm. Ixv. s. 288 ; 

 Ixix. 8. 258. 



t Comptes Eendus, xxv. 383. 



J As this abstract does not appear to he generally known, we here copy it from the report in question: — 



*' These remarkable reactions lead the author to anticipate that zincethyl will prove in the hands of chemists 

 a new and valuable means of research ; for it is evident from its reactions that it will be capable of replacing 

 electro-negative elements in organic or inorganic compounds bj' ethyl ; a kind of replacement which has never 

 yet been attempted, but which the author anticipates will enable him to build up organic compounds from 

 inorganic ones, and ascend the homologous series of organic bodies ; by replacing, for instance, the hydrogen 

 in a methylic compound by chlorine or iodine, and then acting upon this product of substitution by zincethyl 

 or zincmethyl, the author believes that compounds higher in the scries will be obtained, since he regards the 

 higher homologues of methyl and its compounds as derived from the latter radical by the successive replace- 

 ment of hydrogen by methyl." 



§ Ann. der Ch. und Pharm. Bd. ci. s. 260. 



11 Zeitschrift f. Ch. u. Pharm. 1864, s. 30. 



