456 Prof. Wanklyn on the Action of Sodium 



C 5 IPCn n ,„ ,_ Na\ n L C 5 H 9 0\ 

 4 C 2 H 5 J U + d ~ C 2 H 5 J U + C 5 H 9 J ' 



C 5 H 9 0\ n ^ N o Na\ n , C 5 H 9 0\ 



C2H5 )0 + Na 2 = C2H5 jO+ Na |, 



C 2 H 3 0^ N4- Na"l (C«H»0)n 

 d C 2 IPJ U + 1Na - d C 2 H 5 / U NaJ' 



These are the equations by which the action of sodium on 

 ethers of the fatty acids has been explained by me. All of them 

 represent change of the same kind, viz. displacement of the acid- 

 forming radical by sodium. The difference between them re- 

 lates to whether the acid-forming radical is simply isolated, or 

 enters into combination with more or less sodium. 



The first of these equations was given in 1864*. The second 

 was announced last year at the Meeting of the British Associa- 

 tion in Dundee, and is to be found in ' The Laboratory/ p. 409. 

 The third was also given in a modified form in Dundee, but di- 

 stinctly brought forward and insisted upon at the last Meeting 

 of the British Association at Norwich. A report of the paper 

 read at Norwich occurs in the f Chemical News/ 11 Sept. 1868, 

 from which it may be learnt that one of my objections to the theory 

 of Geuther and Prankland and Duppa is, that the equivalent of 

 free hydrogen which they describe as complementary to every 

 equivalent of sodium used up is mythical. 



On the present occasion 1 have to describe particularly the 

 research on valerianic ether wherein sodium-valeryl was ob- 

 tained. 



From the circumstance that so many chemists have worked 

 at this subject with such discordant results, some idea may be 

 formed of the difficulties of the investigation. It is essential to 

 start with pure ethers. The aid derivable from quantitative de- 

 terminations of the yield of product is required in order to make 

 a correct interpretation of the reaction. In the instance of vale- 

 rianic ether, and, in deed, in every case except that of formic, acetic, 

 and propionic ether, there is a further source of perplexity and 

 complication in the circumstance that there are isomers of the 

 fatty acids, and consequently of their ethers. 



Passing on to the description of my experiments : — 



The valerianic ether was titrated, using alcoholic solution of 

 potash, as has been described by me on another occasion. 100 

 parts of the ether neutralized 30* 15 parts of potassium. The 

 theory for pure valerianic ether requires 30'08. The valerianic 

 ether was neutral to test-paper ; and its purity may be looked 

 upon as sufficiently guaranteed by this titration. 



* Journal of the Chemical Society, vol. ii. p. 376. 



