Dr. Ilofmaun on the Pohj-ammonias. 309 



March 11. — Dr. Hooker, Vice-President, iu the Chair. 



The following communication was read : — 



" Notes of Researches on the Poly- Ammo jias." Bv Aus:. W. Hof- 

 mann, Ph.D., F.R.S. &c. 



Former investigations had led me to some general conclusions re- 

 garding the molecular constitution of the organic hases, which I have 

 communicated to the Royal Society, and which have heen published 

 iu the 'Transactions' (1850, p. 93; 1851, p. 357). My experi- 

 ments had proved that each equivalent of hydrogen in ammonium may 

 be replaced by an equivalent of a mono-atomic electro-positive radical, 

 such as methyle, ethyle, &c. ; — a series of compound ammoniums 

 being produced, the salts of which may be thus formulated : — 



pn fRH run r^n 



i TT I ' R' I R' ' I R' ' 



Nin^ci. N^^gki. N^R.>C1. N^^,j>CI. 

 LHJ LHJ LhJ LR'J 



R' representing a mono-atomic electro-positive radical. 

 These successive substitutions were accomplished by the action of 

 amnionia upon the bromides and iodides of the alcohol-radicals, 

 which since that time have become most valuable agents of substi- 

 tution in the hands of chemists. 



All the bases produced by this process being derived from 

 1 equiv. of ammonium, contain 1 equiv. of nitrogen ; they differ 

 in this respect essentially from the majority of the alkaloids extracted 

 from plants, and more'particularly so from those which, like quinine, 

 morphine, strychnine, &c., specially claim our interest. By far the 

 greater number of the vegetable alkaloids contain 2 equivs. of nitro- 

 gen. In some vegetable and animal bases we find even 3 and 4 equivs. 

 of nitrogen. The molecular construction of these bodies is still ob- 

 scure, but it is extremely probable that they are derived from 2, 3 or 

 4 ammonia equivs., in which the hydrogen is more or less replaced 

 by poly-atomic molecules, and that the stability of such complicated 

 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 i)articularly by the classical researches of 

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



Taking as a i)oiut of departure the neutral compounds wliich arc 

 formed by tlie action of amnionia upon bibasic and tribasic acids, 

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

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

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

 In the concei)tion of this analogy there a])pcarcd but little doubt that 

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

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

 treatment of ammonia with the analogous com[)ounds of mono-acid 

 nlcoliols has given rise to the formation of the mon-anunonium 

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



