SIR B. C. BRODIE ON THE ACTION OF ELECTRICITY ON GASES. 
483 
diminution of volume occurs when the oxygen is submitted to the action of electricity, 
I shall further assume that (the unit of oxygen being symbolized as | 2 ) ozone is some 
denser form of oxygen, to which the symbol | 2+ ” (where n is a positive integer) is to be 
assigned. Writing also [£] as the symbol of that “ simple weight” | which is transferred 
to the oxidized substance in the various oxidations effected by ozone, the result of the 
total system of experiments, of which an account has here been given, may be expressed, 
so far as regards the distribution of the matter of the unit of ozone in those reactions, 
by the general equation 
0 + + ” = # + Cp( 2 + w) + ^)[i] , 
where p, q , n are positive integers, p -f- q the number of units of ozone which are effective 
in the reaction, q the number of units of oxygen formed, andp(2 -\-n)-\-qn the number 
of the “ simple weights” [|] transferred. 
We have, then, putting T as the “ titre” of the gas, V — V) as the contraction, S as 
the oxidation, and R— — and r= ~, since T — 
R: 
Ip 
G P + (l)n ’ 
_p(2+n) +qn 
(. p + q)n 
=R + 1. 
Considering the preceding experiments we have four cases brought before us. 
Case I. R=0, r— 1, 
p —0 ; the equation becomes 
r + -=r 
In this case no diminution occurs in the volume of the gas. Examples of this case 
are afforded in the various experiments given in Section II., — namely, the oxidation of 
neutral iodide of potassium, the oxidation of the protochloride and protosulphate of iron, 
and other similar phenomena. These experiments throw no light whatever on the 
value of n, and any assumption as to this value based upon them is purely speculative 
and conjectural. 
Case II. R=l, r= 2, 
p(2—n)=qn. 
Examples of this class are supplied in Section III. ; such are the oxidation of hydriodic 
acid, the oxidation of the strongly alkaline solution of hyposulphite of soda and of the 
pentasulphide of barium. 
We may here make two hypotheses as to the value of n : 
Hypothesis (1) n—1, p=q, whence 
2P=F + 4[g ; 
Hypothesis (2) n = 2, # = 0, whence 
r=4[i]. 
According to hypothesis (1) the density of ozone is once and a half that of oxygen; 
MDCCCLXXTI. 3 U 
