Chemical Combination of Gases. 257 



of the formation of ozone, if we suppose that the molecule of 

 ozone consists of three atoms of oxygen. We may prove, in 

 the same way as before, that if v be the number of ozone 

 molecules and N the total number of oxygen atoms, whether 

 free or in oxygen molecules or in ozone, that 



^=ijgt(N-3„) 3 .... (21) 



if we adopt the first hypothesis, and that 



» 2 =i!-CT(N-3») 3 .... (22) 



l <2 T 3 



if we adopt the second. 



These equations are of exactly the same type, and according 

 to both of them the proportion of ozone formed ought to 

 increase with the density of the oxygen from which it is 

 formed. I am not aware whether this has been observed or 

 not. The decomposition of steam by the silent electrical dis- 

 charge would be a very suitable case for comparing the theory 

 given in this paragraph with experiment ; but though the 

 decomposition has been observed, no quantitative experiments 

 seem to have been made on this subject. In fact no such 

 experiments seem to have been made on the combination of 

 any dyad element with a monad. 



§ 5. We will now go on to investigate the following case 

 which occurs frequently in chemical investigations. Three 

 monovalent gases A, B, C are mixed together in a closed 

 vessel. A can combine with both B and C to form the com- 

 pounds AB, AC respectively; but B and C cannot combine, 

 We wish to find how much of each compound is formed. 



Let m = the number of atoms of A in the vessel. 



n = the number of molecules of A. 



p = the number of atoms of B. 



q = the number of molecules of B. 



r = the number of atoms of C. 



s = the number of molecules of C. 



u = the number of molecules of the compound (AB) . 



v = the number of molecules of the compound (AC) . 



M = the total number of atoms of A in the vessel, 

 whether free or in molecules, or in the com- 

 pounds AB and AC. 



N = the total number of atoms of B, whether free 

 or in molecules of B, or in the molecules of 

 (AB). 



P = the total number ot atoms of C, whether free or 

 in molecules of C, or in molecules of (AC) . 



