427 



March 29, 1860. 



Sir BENJAMIN C. BRODIE, Bart., President, in the Chair. 



The Right Hon. Lord Belper and Dr. W. Bird Herapath were 

 admitted into the Society. 



The following communications were read : 



I. " On the Volumetric Relations of Ozone and the Action of 

 the Electrical Discharge on Oxygen and other Gases." By 

 THOMAS ANDREWS, M.D., F.R.S., and P. G. TAIT, Esq., 

 M.A. Received February 20, 1860. 



(Abstract.) 



This paper contains the full details of the authors' experiments 

 on the volumetric changes which occur in the formation of ozone. 

 From three distinct series of experiments, performed by different 

 methods, they show that when ozone is formed from pure oxygen by 

 the action of the electrical discharge, a condensation takes place, as 

 had already been announced in a former Note published in the 

 * Proceedings.' But the condensation is much greater than the earlier 

 experiments of the authors on the expansion by heat of electrolytic 

 ozone had indicated. It is, in fact, so great, that if the allotropic 

 view of the constitution of ozone be correct, the density of that body, 

 as compared with oxygen, would be represented by a number cor- 

 responding to the density of a solid or liquid rather than that of a 

 gaseous substance. This conclusion follows necessarily from the 

 authors' experiments, unless it be assumed that when ozone comes 

 into contact with such substances as iodine, or a solution of iodide of 

 potassium, one portion of it is changed back into common oxygen, 

 while the remainder enters into combination, and that these portions 

 are so related to one another, that the expansion due to the one is 

 exactly equal to the contraction arising from the other. For the 

 details of the experiments and of the methods of investigation em- 

 ployed, reference must be made to the original paper. 



The second part of the communication is devoted to the action of 

 the silent discharge and of the electrical spark on other gases. 



