122 Henry Riddell on 



The experimenters attempted to discover the density of Ozone 

 when mixed with Oxygen on the assumption that the molecule 

 was completely broken up and the resulting oxygen combined 

 with the reagent employed. They weighed the reagent and found 

 the volume of oxygen it had seized and then found that no volume 

 whatever had been lost from the gas under consideration. Of 

 course if a definite weight of any substance has no volume 

 whatever its density must be infinite, yet the very accuracy of 

 the experiment is seen in the fact that absolutely no change in 

 the volume could be discovered. 



. . 



If we represent Ozone by the formula A which is possible 



0=0 



since the discovery of quadrivalency in Oxygen, we see at once 

 what occurs. When the outer atom is removed from the molecule 

 it will of course be in a very active condition and will be totally 

 absorbed, while the remaining two atoms keep the molecular form, 

 becoming bivalent. As the molecule in both cases has the volume 

 of two atoms of Oxygen there will be no change whatever due to 

 the tearing away of the loosely bound atom. 



A rather interesting memory is connected with these Ozone 

 investigations. When the paper was submitted for the Royal 

 Society in 1860 it was handed to two referees for report. The 

 curious result of the calculations seems to have raised doubt 

 as to the accuracy of the experiments, but it is rather odd that I 

 have found in Sir George Stokes' correspondence with Andrews, 

 the statement that one of the referees still clung to the view that 

 Ozone was a compound of Oxygen and Hydrogen, though all who 

 read Andrews' first paper with attention will admit that he 

 completely disproves this idea. Stokes was a firm and good 

 friend to l^r. Andrews, and of course well known as a scientific 

 investigator himself, but perhaps even better in his official position 

 in regard to the Royal Society, of which he was secretary for so 

 many years, and afterwards president. George Gabriel Stokes 

 was a Sligo man, and was senior wrangler and first Smith's 

 Prizeman in 1(S41. lie was one of our really great mathematical 



