224 On the Destructive Distillation of Animal Substances. 



its class, and examining its constitution in the same point of 

 view, we may consider it as an ammonia, in which three atoms 

 of hydrogen have been replaced by a single radical C 14 H 5 . 

 "While, therefore, an amide is formed by the replacement of one 

 or more atoms of hydrogen in ammonia by an equal number of 

 molecules of a monobasic radical, a nitryle may be viewed as an 

 ammonia with its three atoms of hydrogen replaced by one atom 

 of a tribasic radical ; and in the same manner there must exist a 

 class of compounds, which for the present we may call imides, 

 although they are not comparable with the substances known 

 under that name, in which part of the hydrogen is replaced by a 

 bibasic radical. The different forms of combination possible 

 under this view may be best rendered intelligible if we make use 

 of general formula?, and take X', X", and X'" as representing 

 respectively a monobasic, a bibasic, and a tribasic radical. We 

 have then the following expressions for the different classes : — 



Of these the first three represent either the amides, or the bases 

 described by Wurtz and Hofmann ; the last is a nitryle, and the 

 others are substances at present scarcely known. 



Now as regards the first three classes, it is manifest that they 

 prove amides or bases, according to the properties of the radicals 

 replacing the hydrogen ; and we may fairly argue from analogy 

 that the members of the last may be also either basic or non- 

 basic. The nitryles at present known are all non-basic, but it 

 is my belief that the most probable explanation of the constitu- 

 tion of the bases of the pyridine series is to suppose that they 

 are true basic nitryles, and that, for instance, in pyridine itself, 

 the tribasic radical C 10 H 5 replaces three atoms of hydrogen in 

 ammonia. The opinion thus expressed regarding the constitu- 

 tion of these bases, and even the possibility of such compounds 

 existing, is speculative, but at the same time it is not altogether 

 unsupported by facts, for though we have no bases in which a 

 tribasic radical exists, there certainly are instances in which two 

 atoms of hydrogen are replaced by a bibasic radical. A marked 

 example is found in Gerhardt's platinamine, although there the 

 replacing substance is not a compound but a simple radical. Its 

 formula may be written thus : — 



£}»• 



in which platinum is a bibasic radical replacing two equivalents 



