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



monly employed dissected or structural formulae and changes 

 in the energy of the substances formulated. This conclusion 

 might almost have boon arrived at by a study of structural 

 formulae themselves. Such formulae as 



CH 4 , CH 3 (CH 3 ), CH 3 (C 2 H 6 ), CH 3 (C 3 H 7 ), CH 3 (C 4 H 9 ) 

 toll us that two volumes of each hydrocarbon vapour may be 

 prepared from two volumes of the vapour of the hydrocarbon 

 immediately preceding it by an operation symbolically repre- 

 sented by the replacement of H by a radical having the 

 general formula C rt H 2?i+1 . Now there must be some change 

 in the energy of these hydrocarbons before and after the per- 

 formance of such operations ; and inasmuch as we can ascend 

 the series by a repetition of the same operation, we should 

 expect that the change in energy, whatever it may be, would 

 be regular, and would be related in some way to the regular 

 change in chemical constitution. 



11. Not only do the formulae of compounds indicate the 

 actions by which these substances are produced, and by which 

 they may be transformed into other substances, but with the 

 formulae of the elementary bodies there is likewise associated 

 information of a similar nature. 



Mendel ejeff* has pointed out that if the symbols of the 

 elements be arranged in the order of their combining weights, 

 beginning with the smallest, the elements may be divided into 

 groups and series, the members of which are characterized by 

 a gradation of properties, which gradation is closely related to 

 the increase of the combining number. Each group possesses 

 many properties in common, among these the power of 

 forming oxides and other salts of similar type being very 

 marked. We have here, then, a possible arrangement of che- 

 mical symbols such that, from its position in a regular series, 

 each symbol shall tell us a great deal concerning the power of 

 doing of the element which it symbolizes. 



12. It appears to me, therefore, that our chemical formulae 

 do tell us very much about the actions of the substances 

 formulated, about their methods of formation and of decom- 

 position, and that as advances are made in a knowledge of the 

 changes of energy, which are undoubtedly correlated with 

 changes in chemical constitution, these formulae may be so 

 modified as to express such knowledge. At present we know 

 so little of chemical kinetics that it would be altogether pre- 

 mature to propose any method for giving symbolic expression 

 to the few facts which have been brought to light. 



13. In the symbolic expressions of chemical actions such 



* Ann. Ckem. Pharm. Suppl. vol. viii. p. 133. 



