10 Mr. M. M. P. Muir on Chemical Notation. 



those symbolically. And at present it would be useless to 

 attempt such a task ; we are but on the threshold of such 

 inquiries ; we have been so long (perhaps too long) occupied 

 with gathering together facts concerning the substances pro- 

 duced by chemical action that we have had little time to devote 

 to a closer study of the action itself in its various phases. Such 

 study will form a part of the chemistry that is to be ; and will 

 without doubt be rich in results of the highest importance. 

 But granted that we cannot now express the process of a 

 chemical change in our notation, this does not at all prove 

 that the notation is founded on a false system. We know 

 that one of the best-grounded generalizations of science is 

 expressed by saying, that those substances which we call 

 chemical elements, when they react together so as to form 

 compounds (that is, bodies in which the characteristic pro- 

 perties of the reacting elements are merged), do so in simple 

 multiples of a certain fixed number, — that the composition of 

 the compounds may therefore be expressed by writing the 

 names (or symbols) of the elements, with numbers attached to 

 each expressive of the multiple of the certain fixed number 

 which had before been assigned to each element*. 



This statement merely generalizes a vast number of ob- 

 served facts. Unless we are to take the results of each indi- 

 vidual experiment as expressive of the exact truth as regards 

 the composition of the substance under examination, in which 

 case a science of chemistry would be impossible, we must 

 accept such a statement as this. As our chemical notation is 

 founded on this generalization from facts as one of its main 

 supports, it follows that the results of future experiments in 

 the direction of tracing the exact steps of chemical action, and 

 of measuring the various forces which there come into play, 

 whatever the results may be, cannot overthrow our present 

 system of notation ; they may cause us to modify it greatly, 

 perhaps so greatly that one who had been accustomed to the 

 old would hardly recognize the new notation as in any way 

 connected with it. Nevertheless we may be certain that the 

 process will involve no breach of continuity. 



20. But I must now pass on to consider chemical notation 

 in the light of that theory which appears to me to explain the 

 best-known facts of material science in a more thorough and 

 satisfactory manner than any which has as yet been proposed: 

 I mean the Molecular Theory of Matter. 



21. And in the first place I would insist upon the truth of 

 Dr. Wright's remark (loc. cit.), that neither this theory nor 

 the atomic theory, generally so called, is taken for granted in 



* See Wright, Phil. Mag. [IV.] vol. xliii. p. 505. 



