356 



minous envelope of the sun were tlien considered ; and an attempt 

 was made to show that the shining particles in that envelope may 

 possibly be minute luminiferous organisms, floating in an elastic 

 atmosphere, each emitting only a small amount of phosphorescence, — 

 the enormous flood of splendour emanating from the surface of the 

 medium being due to the combined action of these individually feeble 

 agents. 



The following Gentlemen were duly elected Ordinary 

 Fellows : — 



Hon, Lord Neaves. 

 Dr Penny, Glasgow. 



Monday, ISth February 1856. 



Right Rev. Bishop TERROT, V.R, in the Chair. 



The following Communications were read : — 



1. On certain cases of Binocular Vision. By Professor Wil- 

 liam B. Rogers. Communicated by Professor Kelland. 



The object of this paper was to ascertain, by a geometrical con- 

 struction, the optical appearance presented by the binocular vision of 

 a straight line and a circle, or of two sti'aight lines. The problem 

 discussed was, accordingly, the geometric one of the intersection of a 

 cone with a plane, or of two cones with each other : and the conclu- 

 sion arrived at was that the apparent image is always a conic section. 

 The author took no account of the perspective of the presented com- 

 bination of images, nor of the union or disunion of the extremities 

 of the respective images when their lengths are different. Nor did 

 he allude to the mode by which the mind arrives at connected con- 

 clusions, from separate examination by the eye, whether by i-etention 

 of images on the retina, or by the action of the memory, or other- 

 wise. In anticipation of the introduction of such subjects, which the 

 author has discussed in three papers, printed in Silliman's Journal of 

 last year, Sir D. Brewster addressed the following letter to Prof. 

 Kelland, which puts some of these questions in a striking point of 

 view, and is of considerable interest : — 



" My dear Mr Kelland, — I observe that Pi'ofessor Rogers is to 



