﻿100 Prof. W. A. Norton on the Fundamental 



conception here formed of a molecule involves the idea of the opera- 

 tion of the two forces of attraction and repulsion : a force of attrac- 

 tion is exerted by the atom upon each of the two atmospheres sur- 

 rounding it, and a force of mutual repulsion between the atoms of 

 each atmosphere. These we regard as the 'primary forces of nature, 

 from which all known forces are derived." 



These are the capital points of Professor Norton's ingenious 

 theory. But we think that such a theory contains a great deal of 

 arbitrary assumption. And indeed on what evidence are we to 

 grant that matter exists in three forms essentially different from each 

 other ? Then how can we know the existence of atoms of gross 

 matter having a spherical form, and therefore extended though indi- 

 visible ? Why should we admit two sethereal fluids, which are both 

 repulsive and only differ in subtilty ? All this the learned Professor 

 assumes without proof, apparently because it consists of " established 

 truths and generally received ideas." But we say that no one has 

 up to this day established the proof of such propositions. As for 

 " received ideas," every one knows how often questionable notions 

 have been and are received without serious examination, especially 

 when expressed by professors in a very dogmatic style. Are not a 

 thousand hypotheses received? and do they cease to be hypotheses, 

 although he who makes use of them for building a theory adorns 

 them with the high name of principles ? 



This is all very plausible, but the objections urged are desti- 

 tute of any real force. We will first consider the general intima- 

 tion that the theory rests upon "a great deal of arbitrary 

 assumption." No theory of molecular physics can, in the 

 nature of things, have any other foundation than general prin- 

 ciples to be regarded as hypotheses that have been rendered 

 more or less probable, either by inductions from observation or 

 by a priori reasonings. Molecular physics cannot be erected, 

 like mathematics, upon a foundation known from the first to be 

 eternally sure, that of self-evident truths. Mechanical axioms 

 may exist as mere figments of the mind, and have often risen 

 like bubbles in the minds of speculative philosophers, shone with 

 an evanescent splendour, and suddenly burst at the touch of a 

 hard fact. Our author is another instance of a learned philo- 

 sopher who has faith in such unsubstantialities, and thinks to 

 substitute them as a proper basis for a theory of molecular me- 

 chanics, in place of the general conceptions to which the pro- 

 gress of science leads, and by which alone its highest inductions 

 find any explanation — regards the latter as arbitrary assump- 

 tions, and his own mental convictions of what matter must be 

 and how it must act as the only reliable foundation upon which 

 to build. It is true that he takes exception to Principles 3rd and 

 4th from the inductive point of view. Upon this ground (the 

 only legitimate one to be occupied) I am quite ready to meet 



