THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JULY 1876. 



I. On Chemical Notation. By M. M. Pattison Muir, 

 F.R.S.E., Assistant Lecturer on Chemistry, the Owens 

 College, Manchester* . 



1. ~TN examining a chemical action we may pay attention to 

 J- (1) the substances which take part in, and the final 

 products of, the action, or (2) to the force which is concerned 

 in doing the work. Thus the action of sulphuric acid upon 

 zinc is commonly represented by the equation 



Zn + H 2 S0 4 = ZnS0 4 + H 2 , 

 which tells us that a given weight of zinc acts upon, or is 

 acted upon by, a given weight of sulphuric acid, with the 

 production of certain fixed weights of zinc sulphate and of 

 hydrogen ; and further, the equation implies that a certain 

 amount of force is expended in the action. So again the 

 equation 



2H 2 = 2H 2 + 2 

 not only states, in symbolic language, the fact that 36 parts 

 by weight of water yield 4 parts by weight of hydrogen, and 

 32 parts by weight of oxygen, but it also implies the further 

 fact that, in order to obtain the quantities of hydrogen and of 

 oxygen from water, a certain amount of energy must be 

 altered in form. The latter fact is not, it is true, stated in 

 our ordinary chemical equations in the same prominent manner 

 as the former ; still it is, I think, unmistakably implied. 



2. These two methods of regarding a chemical equation are 

 not without close relationships to each other. In a paper 



* Communicated by the Author. 

 Phil. Mag. S. 5. Vol. 2. No. 8. July 1876. B 



