ON THE STATE OF ORGANIC CHEMISTRY. 7 



We may illustrate this by reference to a substance which has been men- 

 tioned above ; namely, benzamide. We have shown how, according to the 

 particular reactions which we take into consideration, benzamide may be re- 



C 7 H 5 01 C 7 H°N1 



garded either as a nitride or as an oxide ; as H V N, or as H j O. 



Both of these formulae derive from very simple types, but each contains a 

 somewhat complex radicle,— a radicle containing three different elements. 

 If, however, we combine these two expressions, and, by means of a^poly- 



atomic radicle, represent benzamide as deriving from the mixed type jp q J > 



H } N 

 we obtain the formula (C 7 H 5 )"' . 



H }0 



This is a more general expression than either of the other two, for it gives 

 us even more information as to the possible transformations and derivatives 

 of benzamide than both of them taken together. Corresponding formulae 

 for the other members of the benzoic group may be obtained from it by 

 supposing the water or ammonia of the type replaced by other molecules. 

 For example : — 



Benzoic acid 



(C 7 H 5 )'"01 [h}°, 

 H O/' type LH| 



Chloride of benzoyl (C 7 H 5 )'" { £ l , type [^ q, 



H }N fH [ N 



Chloride of benzamidyl (C 7 H 5 )"' j , type H J , 



CI 

 H 1 



Unknown analogue of acediamine ^ H J 1 , type L-H ~\ , 



H '* Jj} N 



Product of the action of pen- 1 f CI TH CI 



tachloride of phosphorus L . (C 7 H 5 )"' j CI, type | H CI, 



on chloride of benzoyl*. . J [ CI lH CI 



Benzonitrile (C 7 H 5 )'" N, type H 3 N. 



In all cases, formulas derived from complex types and containing simple 

 radicles, are of a higher degree of generality than formula- derived from 

 simple types and containing complex radicles. This will become evident 

 if we consider a little the real import of types and radicles. It is clear, in 

 the first place, that a formula derived from a single molecule of any given 

 type, only tells us that the body which it represents can undergo once over 

 the decompositions which characterize that particular type. If we want to 

 express that it can undergo the same decomposition twice or three times, we 

 must represent it as deriving from two, or from three molecules of the same 

 type. Or, if we want to express that it can undergo decompositions of two 



* Schischkoff &.Rosing, Compt. Rend. xlvi. 367 ; Jahresber. 1858, 279. 



