210 CHEMISTRY 



hydrogen and methylene derivatives, and the latter then sponta- 

 neously transform themselves, by intramolecular addition, into penta- 

 and hexamethylene rings. 



On the Reactions of the Paraffines and the Benzene Derivatives 



The reactions of the paraffines and the benzene derivatives towards 

 halogens, nitric and sulphuric acids, whereby substitution products 

 are formed, are still interpreted in the text-books from the standpoint 

 of metalepsis or substitution, although a vast amount of evidence 

 has accumulated which makes this axiomatic assumption improbable. 

 The fact that ethane and benzene, for instance, decompose into hy- 

 drogen and into ethylene and diphenyl at 800 and 600 respectively 

 proves that an extremely small per cent of these molecules must 

 exist at ordinary temperatures in an active or dissociated condition, 



CH 3 CH 3 <=t CH 3 CH 2 h H 



and CH 3 CH = +2H-;orC 6 H 6 <=C 6 H 5 -+H-. 



The same is true of ammonia, H 3 N <= H 2 N |-H and HN = + 2H - 

 and N= +3H, and of a great variety of other non-ionizable hydrogen 

 compounds. 



Consequently when chlorine or nitric acid acts with benzene or 

 ethane to give the monochlor or mononitro substitution products, 

 we have these reagents, in the active molecular condition, simply uniting 

 by addition with the dissociated ethane or benzene particles, 



H C 2 H 5 



o o 



or HO-N-0 + H-C 6 H 5 ->HON-OH. 



The resulting addition products then lose hydrogen chloride and water 

 respectively and thus give the monochlor or nitro substitution pro- 

 duct of the mother substance. From this point of view all so-called 

 substitution reactions belong to the category of addition reactions. 

 What is now especially needed in order to place the reactions of organic 

 chemistry on an exact mathematical basis is a precise method of 

 determining the ratio of active particles present at various tempera- 

 tures in the case of the unsaturated as well as of saturated compounds. 

 As the substances under discussion are almost exclusively non-electro- 

 lytes, the sole methods that suggest themselves for this purpose are 

 determinations of the speed of decomposition as well as of addition 

 reactions. 



The above discussion makes it evident that all unsaturated com- 



