476 On the Influence of Atomic Weight. 



Relative 





rate of 



Limit of 



etherification. 



etherification, 



Methyl alcohol... 



69-5 



Ethyl „ ... 70-5 



66'6 



Propyl „ ... 70-2 



66-8 



Butyl „ ... 69-6 



67-3 



Isobutyl „ ... 66'6 



67-4 



Octyl „ ... 64-4 



72-3 



Cetyl „ ... 



80-4 



A similar relation was also observed as regards the etherifi- 

 cation of secondary alcohols and phenols (Ber. deut. chem. 

 Ges. xi. pp. 2117, 2148). 



The limit of etherification of the alcohols of the paraffin 

 series increases with the molecular weight, except in the 

 case of methyl alcohol. 



In the preceding pages I haye endeavoured to trace and 

 place in a connected form the more important relations be- 

 tween the atomic weights or chemical composition and the 

 various chemical and physical properties of the elements, 

 and more especially of their compounds. In order that this 

 connexion might be rendered the more evident, I have limited 

 myself in great part to those properties which are capable 

 of being represented numerically, and consequently to what 

 are generally termed the physical properties. 



The relations between atomic, molecular, or equivalent 

 weights and specific heats (Dulong and Petit's law), electro- 

 lysis (Faraday's laws), and diffusion of gases (Graham's law) 

 are so well known that I have thought it unnecessary to refer 

 to them in detail. 



With one exception, too, I have omitted all mention of the 

 connexion which undoubtedly exists between chemical com- 

 position and the thermal phenomena of chemical reactions. I 

 reserve the discussion of this interesting subject to a subse- 

 quent communication; for the limits of the present paper 

 would not admit of full justice being done to what I believe 

 to be one of the most important points from which to view 

 chemical decomposition, and which promises in the future to 

 throw most light on the more vexed problems of chemical 

 research. 



