2 Mr. M. M. I\ Muir on Chemical Notation. 



published in this Magazine by Dr. E. J. Mills, it is said that 

 chemical substances are valued not for what they are con- 

 ceived as being, but as doing — that the most important ques- 

 tion with regard to a chemical substance is, how does it 

 behave with this or that reagent? It appears to me that 

 what a chemical substance does depends very much upon 

 what it is, and that, although we are obliged to study these 

 questions to a certain extent apart, we shall some day be able 

 to express by one and the same formula the constitution and 

 the various modes of action of all known chemical bodies. 



3. In the following paper I shall endeavour to point out 

 what appear to me to be some of the reasons for maintaining 

 our ordinary formulae, but at the same time, for supplement- 

 ing them by investigations into, and symbolic representations 

 of, the dynamical laws governing chemical transformations. 



4. In the first place, all questions as to work done by 

 different chemical substances imply the existence of these sub- 

 stances : change in the form of energy implies the existence 

 of energy ; but the existence of energy implies, to our minds 

 at any rate, a something which is the seat or vehicle of 

 energy. This something is matter. Matter has been defined 

 by two eminent naturalists as " that which is essential to the 

 existence of the known forms of energy, without which there- 

 fore there could be no transformations of energy." The 

 physical universe is often compared to a machine, the laws of 

 the working of which are the laws of energy ; but an investi- 

 gation into these laws surely does not preclude, but rather 

 prompts to an investigation into the structure of the machine 

 itself. It may be urged that what we call matter has no 

 existence outside of the mind of the observer ; this objection, 

 however, has been often refuted*. 



5. One of the most well-founded generalizations concerning 

 matter is to the effect that no particle of it can be destroyed, 

 nor be produced by us. The mass of matter cannot be 

 changed by us : its form may be changed, the forms of its 

 energy may be altered ; but its quantity remains the same. If 



* 'Unseen Universe,' 1st edit. p. 71. " Some extreme thinkers write 

 as if the}' would persuade us that a species of hallucination affects with 

 similar impressions every individual mind, so that, for instance, one man 

 may usefully warn another about a pitfall on a dark road, and so save 

 him from a catastrophe which might otherwise be caused by something 

 which exists, if at all, in the mentor's mind only, — at all events not as 

 yet in that of his pupil ; though if the warning be unheeded, or not 

 given, there will presently be another mind in which the pitfall will 

 certainly exist with startling vividness. But this is altogether repugnant 

 to every conviction which experience (our only guide in such matters) 

 enables us to form, &c." 



