128 Dr. E. J. Mills on the Atomic Theory. 



bility. The word atom, which can never be used without in- 

 volving much that is purely hypothetical, is often intended to be 

 used to express a simple fact ; but, good as the intention is, I 

 have not yet found a mind that did habitually separate it from 

 its accompanying temptations ; and there can be no doubt that 

 the words definite proportions, equivalents, primes, &c, which 

 did and do express fully all the facts of what is usually called 

 the atomic theory in chemistry, were dismissed because they 

 were not expressive enough, and did not say all that was in the 

 mind of him who used the word atom in their stead ; they did 

 not express the hypothesis as well as the fact. But it is always 

 safe and philosophic to distinguish, as much as is in our power, 



fact from theory ; and considering the constant tendency 



of the mind to rest on an assumption, and, when it answers every 

 present purpose, to forget that it is an assumption, we ought to 

 remember that it, in such cases^ becomes a prejudice, and inevi- 

 tably interferes, more or less, with a clear-sighted judgment." 

 Now, of the two constituents of matter, space is the only 

 continuous one. Consider, then, the case of shellac, a non- 

 conductor. Space, in it, must be an insulator, whatever the 

 atoms may be; for if it were a conductor, the shellac could not 

 insulate. But now take the case of platinum, which must also 

 be composed of atoms and space. Since platinum is a conductor, 

 space, being its only continuous constituent, must be a conductor. 

 Space, which is everywhere uniform, is therefore a conductor 

 and a non-conductor. "Any ground of reasoning which tends 

 to such conclusions as these must in itself be false." The facts 

 do not warrant any other conclusion than that what we call 

 "matter is continuous. Indeed "a mind just entering on the 

 subject may consider it difficult to think of the powers of matter 

 independent of a separate something to be called the matter) but 

 it is certainly far more difficult, and indeed impossible, to think 

 of or imagine that matter independent of the powers. Now the 

 powers we know and recognize in every phenomenon of the crea- 

 tion, the abstract matter in none ; why then assume the exist- 

 ence of that of which we are ignorant, which we cannot conceive, 

 and for which there is no philosophical necessity V 



If we must assume at all, let us assume as little as possible. 

 The system of Boscovich is in these respects superior to the 

 atomic ; it assumes much less, and does not contradict the facts 

 of nature. In it Matter and the atom disappear; and we find 

 that substances are constituted of centres of force, attractive and 

 repulsive. For the shape of the atom, the direction and relative 

 intensity of these individual forces are substituted. " Matter is 

 not merely mutually penetrable, but each atom " (centre) " ex- 

 tends, so to say, throughout the whole of the solar system, yet 

 always retaining its own centre of force." 



