398 



THE 



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change of conditions, the characteristics of the two sub- 

 stances alter radically, in a way quite diverse from that 

 which our formulation hitherto has given us; in place 

 of the two gases H and () there appears, for example, 

 water. The science of chemistry deals with multitudes 

 of these sudden changes, which are quite out of line with 

 what is observed before precisely the necessary condi- 

 tions are reached for producing them. 



27. Now, among the things which have to be learned 

 empirically are the effects of con fif/x rations. This is 

 true even on the most strictly mechanistic view. The 

 laws of the motion of a body when the configuration is 

 such that forces from two other bodies act upon it at 

 right angles had to be learned by experience, before they 

 could be used in prediction. By varying the position of 

 the bodies, the angles of the directions of the forces, the 

 number of bodies or forces, etc., the laws of such varia- 

 tions were worked out, till now we have an extensive 

 system that can be used in prediction. In chemistry we 

 have a set of rules as to the effects of configuration that 

 are not apparently continuous with the rules obtained 

 in the way just set forth; the rules for the results when 

 H and O are in one combination or another; when C, H 

 and O, are in one configuration or another, had to be 

 learned by experience in each case. We have thus in this 

 direction a large store of propositions regarding config- 

 urations, that may be used in prediction. But for what 

 will happen under any configuration never before ex- 

 perienced the only test is experience. It would have been 

 quite impossible, for example, from a knowledge of what 

 happens in the configurations given by the compounds of 

 copper to predict the laws for the configurations given 

 by compounds of carbon. 



28. Application to the "Doctrine of Organic Auton- 

 omy/' — This asserts, as we have seen, that with a knowl- 

 edge of "all the laws of motion of inorganic particles 

 and of the actual configuration of the particles compos- 



