Sir B. C. Brodie on the Action of Electricity on Gases. 4^73 



mean of 1/ experiments made with the neutral hyposulphite gave 

 2'02 as the value of this contraction; and the mean of 10 experi- 

 ments made with the slightly alkaline hyposulphite gave for it the 

 same value. 



It is hence to be inferred that the oxidation effected in these 

 cases is equal in amount to three times the oxidation effected by the 

 same gas in neutral iodide of potassium. 



Similar experiments made with oil of turpentine entirely confirmed 

 the view of Soret as to the amount of contraction which the gas 

 undergoes when acted upon by this substance, the mean of eight ex- 

 periments giving 2*02 as the value of the contraction. 



The investigation of the effect due to the action of the electrized gas 

 upon protochloride of tin is attended with considerable difficulty, 

 from the circumstance that a solution of protochloride of tin is 

 readily oxidized by the action of pure oxygen. The difficulty was 

 met in two ways, both of which led to the same conclusion, namely : — 

 by applying a correction for the oxidation effected by the oxygen 

 with which the ozone was associated ; and by using very dilute solu- 

 tions of the protochloride of tin, in which this oxidation is reduced 

 to a minimum. In two experiments conducted on the latter prin- 

 ciple, and in which the oxidation, as well as the contraction, was ex- 

 perimentally determined, the value of the contraction was found to 

 be 2' 19 and 2 33, while the oxidation in the two experiments respec- 

 tively was 3-12 and 3'07. 



Using the notation employed by the author in a previous communi- 

 cation* to the Royal Society, and putting C as the symbol of the unit 

 (that is of I'OOO cub. centim. at 0° and 760 millims.) of oxygen, and 

 putting [^] as the symbol of that simple weight E, transferred to the 

 oxidized substance in the various oxidations effected by the ozone, 

 and further assuming that ozone is to be regarded as some denser 

 form of oxygen, to the unit of which the symbol ^2+*^ (where n is 

 a positive integer) is to be assigned, the result of the total system 

 of experiments of which the account is given in this memoir may 

 be expressed, so far as regards the distribution of the matter of the 

 unit of the ozone, in the various reactions by the general equation 



(p + q) l^+- = qe + (p(2 + ^) + qn) [^ , 

 where j9, q, n are positive integers. 



The investigation of the various hypotheses originating in this 

 equation leads to the conclusion that the hypothesis that the unit of 

 ozone is composed of three simple weights, £, and is to be symbo- 

 lized as ^^ is both necessary and sufficient for the explanation of the 

 total system of phenomena, and that no other hypothesis of the order 

 referred to is tenable. 



* Vide " Calculus of Chemical Operations," by Sh* B. C. Brodie, Bart., 

 F.R.S., Phil. Trans. 1866, pp. 781-859. 



