36 NOMOS. 



platinum, and copper, are both composed of zinc, 

 platinum, and copper, two atoms (perhaps) going 

 to form the positive element, and a single atom 

 (perhaps) going to form the negative element ; but 

 the elements of a molecule of hydrochloric acid are 

 of different substances, the positive element being 

 chlorine, the negative hydrogen. Let it also be 

 supposed that new molecules may be formed by the 

 combination of various positive and negative ele- 

 ments, and there appears to be no great difficulty in 

 reducing all the phenomena of the galvanic circuit 

 to the chemical hypothesis. 



That this is the case we will endeavour to show 

 in the following series of diagrams. In this series 

 we will indicate the different parts of the galvanic 

 circuit by their respective chemical symbols the 

 zinc plate by zn, the platinum plate by P, the 

 copper connecting wire by C u, and the hydrochloric 

 acid with which the cell is charged by HC/. We 

 will suppose, moreover, that each of these parts 

 consists of two molecules, each consisting of its two 

 elements. The two elements of the zinc, platinum, 

 and copper molecules are composed of the same 

 substance, and we will therefore represent these 

 molecules by doubling the symbols, and placing 

 an accent over that which is to represent the 

 positive element. The two elements of the hydro- 

 chloric acid molecules are composed of different sub- 

 stances, the hydrogen, H, being the negative, and 

 the chlorine, C I' ', the positive. Thus : 



