134 HISTORY OF CHEMISTRY. [LECTURE VIII. 



without condensation, is evidence in favour of the view that 

 this compound, alcohol, is a hydrate of ether. ... In the 

 formation of benzoic ether from absolute alcohol and benzoyl 

 chloride, we perceive a simple decomposition of water, which 

 does not extend further than to the water of hydration." 



Liebig went too far in his argumentation, and Zeise and 

 Dumas justly protested against it. The former repeats his 

 previous examination of the inflammable platinochloride, and 

 finds his first results confirmed : there is no more oxygen 

 present in the compound from which the water of crystallisation 

 has been removed, and, therefore, ether cannot be assumed to 

 be present in it, but only etherin. 16 Dumas likewise upholds 

 his earlier experiments. 17 He points out the difference in the 

 action of aqueous and of dry gaseous ammonia upon oxalic 

 ether. In the first case only, is oxamide formed, whereas 

 ammonia gas gives rise to the substance he had previously 

 described, which he now calls oxamethan, and to which he 

 assigns the formula C 4 O 3 ,NH3,C 4 H 4 [C = 6]. 18 As a conse- 

 quence, Dumas also adheres to his old opinion. He draws 

 attention likewise to the fact that it was with him the idea 

 originated according to which ordinary ether ("sulphuric 

 ether ") is the base of the compound ethers ; and he states 

 that it is, in point of fact, the essence of the whole ethyl theory. 

 He goes a step further, indeed, inasmuch as he regards ether 

 itself as composed of water and olefiant gas. 



In this Dumas was right. There was one point, however, 

 which had previously been brought forward by Liebig, 19 on 

 which Dumas and Liebig differed. This was the assumption 

 by Dumas that in ether two of the hydrogen atoms play a 

 different part from the others : and Liebig contested this 

 particular point. The discovery of the mercaptans by Zeise 20 

 furnishes Liebig with an opportunity to adduce new proofs of 



16 Annalen. 23, I. 17 Ann. Chim. [2] 54, 225. Annalen. 10, 277 ; 

 *5> 5 2 - 1S It seems as if Dumas, in accordance with his earlier experiments, 

 assumed one atom of water more ; the analyses do not, however, afford any 

 sharp decision respecting this. 19 Annalen. 9, 15. 20 Ibid. II, I. 



