594 



and its properties render it probable that it will be found to be iso- 

 meric with the product of decomposition previously mentioned. I am 

 engaged in a more minute examination of this compound, which I 

 hope may assist in explaining the cause of the still enigmatical iso- 

 merism exhibited by the derivatives of phenylamine. 



I have already repeatedly called attention to the different atomicity 

 exhibited by nitrogen under different conditions. Tn the derivatives 

 of amidobenzoic and of anthranilic acids, it can be proved that 

 1 equiv. of nitrogen replaces 1 equiv. of hydrogen ; while in the 

 derivatives of phenylamine, the nitrogen is present with the value 

 of three molecules of hydrogen. 



The experiments which I have described were performed in Dr. 

 Hofmann's laboratory. 



IX. " Contributions towards the History of the Monarchies." 

 No. III. Compound Ammonias by Inverse Substitution. 

 By A. W. HOFMANN, LL.D., F.R.S., &c. Received July 

 24, 1860. 



Many years ago I showed that the bromide or iodide of a quartary 

 ammonium splits under the influence of heat into the bromide or 

 iodide of an alcohol-radical on the one hand, and a tertiary moriamine 

 on the other. 



Having lately returned to the study of this class of substances, I 

 was led to examine the deportment, under the influence of heat, of 

 the tertiary, secondary, and, lastly, of the primary monammonium- 

 salts. 



Experiment has shown that these substances undergo an ana- 

 logous decomposition. The chloride of a tertiary monammonium 

 when submitted to distillation yields, together with the chloride of an 

 alcohol-radical, a secondary monamine ; the chloride of a secondary 

 monammonium, together with an alcohol-chloride, a primary mona- 

 mine ; lastly, the chloride of a primary monammonium, the chloride 

 of an alcohol-radical and ammonia. 



Exactly, then, as my former experiments show that we may rise in 

 the scale by replacing the four equivalents of hydrogen in ammonium 

 one by one by radicals, so it is obvious from these new experiments 



