Mr. A. S. Couper on a New Chemical Theory. 107 



often pursued. In mathematics the starting-point is not gene- 

 ralizations, but axioms, ultimate principles. In metaphysics 

 Descartes led the way of progress by analysing till he thought 

 he could reach some ultimate elements beyond which it was im- 

 possible for him to go, then studying their force and power, and 

 proceeding synthetically. The recognition of this method wrought 

 the regeneration of science and philosophy. 



On the other hand, look where Gerhardt's generalization of 

 Williamson's generalization leads him, and legitimately too, — a 

 fact which his logical spirit clearly discerned. He is led not to 

 explain bodies according to their composition and inherent pro- 

 perties, but to think it necessary to I'estrict chemical science to 

 the arrangement of bodies according to their decomposition, and 

 to deny the possibility of our comprehending their molecular 

 constitution. Can such a view tend to the advancement of 

 science ? Would it not be only rational, in accepting this veto, 

 to renounce chemical research altogether ? 



These reflections naturally lead to the inquiry after another 

 theory more adequate to satisfy the just demands which can be 

 made upon it. There is one which, as it is still supported by 

 many distinguished chemists, cannot be passed over altogether 

 unnoticed. It is that of the theory of certain combinates in 

 organic chemistry which are to be viewed as analogous to, "play- 

 ing the part of," inorganic elements. These are denominated 

 radicals, and are supposed to be contained in all organic chemi- 

 cal products. 



In addition to this, and also in connexion with it, there is a 

 doctrine describing many combinates to be copulated, con- 

 jugated, by addition. 



It is impossible here to enter upon any extensive criticism of 

 this theory. I can only remark that it is not merely an unpro- 

 fitable figure of language, but is injurious to science, inasmuch 

 as it tends to arrest scientific inquiry by adopting the notion 

 that these quasi elements contain some unknown and ultimate 

 power which it is impossible to explain. It stifles inquiry at the 

 very point where an explanation is demanded, by putting the 

 seal of elements, of ultimate powers, on bodies which are known 

 to be anything but this. 



Science demands the strict adherence to a principle in direct 

 contradiction to this view. That first principle, without which 

 research cannot advance a step, dare not be ignored ; namely, 

 that a whole is simply a derivative of its parts. As a consequence 

 of this, it follows til it it is absolutely neces.sary to scientific unity 

 and research to consider these bodies as entirely derivative, and 

 as containing no secret ultimate power whatever, and that the 

 pro|>ertie8 which these so-called quasi elements possess are a 



