152 



structures essentially depends upon the substituting capacity of their 

 replacing molecules. 



It was long my intention to extend my researches to the poly- 

 ammonium bases. But my attention has been specially called to 

 the subject by the beautiful results obtained of late, especially in 

 France, by the study of the poly-acid alcohols, by the experiments of 

 M. Berthelot, and more particularly by the classical researches of 

 M. Wurtz, which enable us to take a general view of this subject. 



Taking as a point of departure the neutral compounds which are 

 formed by the action of ammonia upon bibasic and tribasic acids, 

 the diamides and triamides, derived respectively from 2 or 3 equivs. 

 of ammonia, it became extremely probable that the action of ammonia 

 upon poly-acid alcohols would give rise to poly-ammonium bases. 

 In the conception of this analogy there appeared but little doubt that 

 ammonia, under the influence of the bromides and iodides of bi-acid 

 alcohols, would furnish a series of bi-ammonium bases, exactly as 

 treatment of ammonia with the analogous compounds of mono-acid 

 alcohols has given rise to the formation of the mon-ammonium 

 bases above referred to. In other words, it was to be expected that 

 a compound ether R" Br 2 or R" I 2 (R" representing a bi-atomic 

 electro-positive radical) would act upon two equivalents of ammonia, 

 producing a series of salts expressed by the following formulae : 



Br 2 . 



In endeavouring experimentally to verify this idea, it became necessary 



