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



fixed conditions, from a mixture of certain weights of the two 

 former a weight of the third equal to the sum of these two 

 weights is invariably produced. In such a statement nothing 

 is said of the homogeneity or non-homogeneity of the three 

 substances : whatever views may be held on this subject, the 

 fact of the production of the third substance by the mutual 

 action of the other two is undeniable ; and this fact is sym- 

 bolically expressed in the equation we have been considering. 

 Of course chemists are generally in the habit of conceiving 

 that water is made up of oxygen and hydrogen, that these 

 substances exist in some way in the new substance formed by 

 their action upon one another; and the equation will bear this 

 meaning. On the other hand, it is at least possible, in the 

 light of Mr. Lockyer's recent spectral researches, to imagine 

 that hydrogen and oxygen may themselves be split up into 

 simpler substances (just as water is split up into hydrogen 

 and oxygen) ; but if this be the case the equation may remain 

 unaltered : it expresses a truth, although probably not the 

 whole truth. But we believe that chemical equations tell us 

 much more about the composition of substances than the mere 

 fact that certain weights of two bodies produce a certain 

 weight of a third ; this part of the subject, however, I shall 

 defer to a later portion of the paper. 



7. If we are to regard chemical substances chiefly in the 

 light of what they do, it may, apparently, be urged that our 

 ordinary formula? are of little use to us — that, inasmuch as 

 these formulas are based upon statical ideas, they are useless, 

 or all but useless, when we come to deal with questions of 

 kinetics. 



If we investigate chemical formulae, especially in their more 

 recent outcome. I think we shall see that this is a mistaken 

 idea. 



8. Some chemists have affected to sneer at the " pictures," 

 as they call them, which " deface " the pages of so many 

 modern treatises. If they have convinced themselves that 

 " Ignorance is bliss," then they are right in the conclusion 

 " 'Tis folly to be wise." That the use of structural or dis- 

 sected formulas may be carried to a pitch which does become 

 ridiculous — especially in the case of compounds about which 

 we know little or nothing, but whose graphic formulas are, it 

 would appear for that reason, to be continually sketched — can 

 scarcely be denied. But why do chemists make use of such 

 formulas at all ? is it not because they wish to express in the 

 shortest possible manner the greatest amount of information 

 about the actions of the substances formulated ? Instead of 

 putting down in words what this body will do under certain 



