82 Intelligence and Miscellaneous Articles. 



been greatly enlarged ; for of the bodies which had been stranded 

 so many new species and even new forms had been observed, that 

 hardly two had been found to be identical. 



Professor Miller exhibited two new forms of heliotrope, explaining 

 at the same time the difficulties in signalling, which they were in- 

 tended to overcome, commenting upon the relative merits of those 

 invented by Gauss, Steinheil, and others, and explaining the spe- 

 cial advantages of the two which he exhibited. 



Professor Miller also communicated a Supplement to the Crystal- 

 lographic method of Grassmann. 



Mr. G. F. Browne, St. Catherine's College, communicated some 

 Notes upon some Ice-caves explored during the summer of 1865. 

 Two of these he had visited during the previous summer, and he 

 found that there was a somewhat greater quantity of snow in the 

 caverns than there had formerly been. In the first cave he again 

 examined a pit in the ice about 70 feet deep, but, owing to the dan- 

 gerous condition of the ice, was unable to descend into it. In the 

 second cave he had again cut through a curtain of ice into an icy 

 tunnel ; but this year the diameter of the tunnel was so much smaller 

 that he was unable to descend it, although provided with ropes for 

 the purpose. He described some flies found inside the tunnel. The 

 third cave had not previously been explored ; it was an oval in shape, 

 with a level floor of ice. He had descended for about 12 feet 

 between the ice and the rock, and there found a narrow tunnel which 

 appeared to lead to a subglacial reservoir containing water. He 

 ascertained that the ice was at least 24 feet thick ; but it was impos- 

 sible to descend the tunnel. 



Mr. Bonney, who had accompanied Mr. Browne, made some ob- 

 servations on the general character of the country, expressing his 

 opinion that the glacieres were formed by the accumulation of snow 

 in suitable fissures ; and remarking that the prismatic structure of 

 the ice noticed last year by Mr. Browne was very conspicuous. 



X. Intelligence and Miscellaneous Articles. 



ON THE DENSITY OF OZONE. BY M. SORET. 

 (Abstract of a letter to Professor Tyndall.) 

 T OUGHT to have written to you sooner, but I have been much 

 ■*■ engaged in trying to finish part of my investigation on the density 

 of ozone, of which I have spoken to you. You are aware of the dif- 

 ficulties of the question, and of the impossibility of determining this 

 density by weighing ; for, on the one hand, ozone is never obtained 

 quite pure, and, on the other, bodies like iodide of potassium do not 

 absorb ozone, but merely part of its constituent atoms, without 

 change of volume. You are familiar with the hypothesis which I 

 have suggested, which is analogous to that of Weltzien, adopted 

 by Clausius; it consists in considering ordinary oxygen as con- 

 sisting of two atoms O O, and ozone of three 0,0. On this 

 hypothesis the density of ozone ought to be one and a half times as 

 much as that of ordinary oxygen. 



I have therefore endeavoured to arrive at this value, and I believe 



