66 MOLECULAR CONSTITUTION 



thought that certain compounds of carbon with other elements, 

 known as ' organic ' substances, were capable of being produced 

 only within these laboratories of nature, A department of 'in- 

 organic chemistry ' had hitherto existed, separated quite definitely 

 from another known as 'organic chemistry.' In the former 

 were included all those elements and their compounds that were 

 naturally met with among, and which made up, the not-living 

 constituents of our globe ; while under the latter department were 

 ranged such compounds as proteids, carbohydrates, fats and their 

 derivatives which were supposed to be produced only in plants 

 and animals. 



The so-called organic compounds were for a long time regarded 

 as altogether pecuUar ; not as regards their components — for they 

 were known to be composed of precisely the same elements as 

 were most abundant in the inorganic world — but rather in point 

 of origin. They were the products only of living things — had 

 been produced under the influence of ' vital ' forces. The action 

 of physical forces in the world without was deemed inadequate 

 to give rise to such combinations ; and therefore they were 

 separated by a hard and fast line from all other compounds with 

 which the chemist manipulated. Thus the popular belief of the 

 time concerning ' life ' was fostered ; and an argument for the 

 special and peculiar nature of the 'vital forces,' could, at least, 

 be based on the supposed fact that living things produced sub- 

 stances — were in fact almost entirely composed of material 

 combinations — which could not be evolved by the agency of 

 mere physical forces, either in the grand laboratory of nature, 

 or under the hands of the chemist. But now all this has changed. 

 Chemists have already succeeded in building up many hundreds of 

 such compounds, and, as each month passes, the list is swelled by 

 fresh conquests. The speciality then of these compounds has 

 passed away ; the difference between organic and inorganic 

 chemistry is fast vanishing — has, in fact, well-nigh vanished. 



Members of this great group of albuminous or proteid compounds 

 always contain, as principal and fundamental ingredients, carbon, 

 oxygen, hydrogen, and nitrogen, and to these are commonly 

 added traces of sulphur and phosphorus. The first four elements 

 are, however, all-essential, and it is especially worthy of remark 

 that no less than three of them are gaseous. Herbert Spencer 

 says ' : — " When we remember how these re-distributions of 

 ' " Principles of Biology," vol. i., chap, i., ' Organic Matter.' 



