LIMITS OF CHEMICAL SCIENCE. 93 



to include an account of the ores of a substance, as a part of 

 the science which formulates its molecular constitution and 

 the constitutions of all the definite compounds it enters 

 into? I shall be very much surprised if I find that they 

 do. Chemists habitually prefix to their works a division 

 treating of Molecular Physics ; but they do not therefore 

 claim Molecular Physics as a part of Chemistry. If they 

 similarly prefix to the chemistry of each substance an out 

 line of its mineralogy, I do not think they therefore mean to 

 assert that the last belongs to the first. Chemistry proper, 

 embraces nothing beyond an account of the constitutions 

 and modes of action and combining proportions of substances 

 that are taken as absolutely pure ; and its truths no more 

 recognize impure substances than the truths of Geometry 

 recognize crooked lines. 



Immediately after, in criticizing the fundamental dis 

 tinction I have made between Chemistry and Biology, as 

 Abstract- Concrete and Concrete respectively, Prof. Bain 

 says : 



&quot;But the objects of Chemistry and the objects of Biology are 

 equally concrete, so far as they go ; the simple bodies of chemistry, 

 and their several compounds, are viewed by the Chemist as concrete 

 wholes, and are described by him, no.t with, reference to one factor, 

 but to all their factors.&quot; 



Issue is here raised in a form convenient for elucidation 

 of the general question. It is true that, for purposes oj 

 identification, a chemist gives an account of all the sensible 

 characters of a substance. He sets down its crystalline 

 form, its specific gravity, its power of refracting light, its 

 behaviour as magnetic or diamagnetic. But does he there 

 by include these phenomena as part of the Science of 

 Chemistry ? It seems to me that the relation between the 

 weight of any portion of matter and its bulk, which is 

 ascertained on measuring its specific gravity, is a physical 

 and not a chemical fact. I think, too, that the physicist 



