92 Rev. C. Trotter. Physical Properties of Ice [Jan. 29, 



enables one more readily to study it in its different stages ; although, 

 on the other hand, the number of leucocytes which are passing into 

 the lacteals and there undergoing disintegration is much less at any 

 one period than in the mammal. 



A fuller account of the subject, furnished with illustrations, and 

 containing the necessary references to other articles dealing with 

 the same question, will appear in the forthcoming number of the 

 "Monthly International Journal of Anatomy and Histology." 



January 29, 1885. 



THE TREASURER in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : — 



I. " On some Physical Properties of Ice and on the Motion of 

 Glaciers, with special reference to the late Canon Moseley's 

 objections to Gravitation Theories." By the Rev. Coutts 

 Trotter, M.A., Fellow of Trinity College, Cambridge. 

 Communicated by Professor Stokes, Sec. R.S. Received 

 December 22, 1884. 



I. Introductory. 



It will be remembered that in a paper " On the Descent of 

 Glaciers," read to the Royal Society on the 19th of April, 1855 

 (" Proc. Roy. Soc," vol. 7, pp. 333—342 ; " Phil. Mag.," vol. x, 

 pp. 60 — 67), Canon Moseley proposed a new theory io account for the 

 phenomena of glacier motion. The theory was suggested, as is well 

 known, by the observation of the gradual descent of a sheet of lead 

 resting on a roof of moderate slope, and exposed to considerable 

 diurnal variations of temperature. According to it the descent of a 

 glacier is due to the alternate expansion and contraction of the ice in 

 the direction of the length of the glacier under the influence of vary- 

 ing temperature ; gravity assisting the downward and opposing the 

 upward movement of the mass. 



This paper was effectively answered by Forbes (" Proc. Roy. Soc," 

 vol. 7, p. 412), and the theory has never been accepted by persons 



