CHEMICAL STATICS 13 



These three fundamental laws are explained on the 

 atomistic hypothesis. Assuming that the elements chlorine, 

 silver, and iodine occur in discrete particles of fixed mass 

 atoms (chlorine Cl 35-5, silver = Ag = 1 08, iodine = I 

 = 127) we have : 



1. In the symbol AgCl for the particles of which silver 

 chloride consists, the expression for its constant composition. 



2. In the symbol AgC10 3 for silver chlorate the expression 

 that here chlorine and silver combine in the same pro- 

 portion as in silver chloride ; whilst the formulae IC1 and 

 ICL or generally I. m Cl w and I^Cl g refer directly to the in- 

 tegral relation between the proportions in which iodine 

 and chlorine occur in the later example: 



ml >I m p 



- : = ~ :- = ma : np. 



~ - 

 qCl n q 



3. The constant or multiple ratio of combination between 

 chlorine and iodine indirectly (combined with equal 

 amounts of silver) and directly is equally expressed by 

 the three general symbols 



AgpCl,, A gr l s) I W C1 M , 



since the ratios of the halogens combined with the same 

 amount of silver and the direct ratio of combination are 

 given by 



qCl si qrCl . nCl 



^-r : r = - r and -=- , 



r - r -=- 

 rAg psL ml 



whilst 



grCl nCl 



- T- : =- = arm : pen. 

 psL ml 



It may be added that the assumption of the invariability 

 of these atoms in quantity and quality is a simple expres- 

 sion of the empirical law of the conservation of mass and 

 of the invariability of the elements. 



The molecular hypome&is is a direct consequence of the 

 assumption of atoms, and so rests also on a chemical basis. 



