CAPILLAR Y A TTRACTION. (APP. B.} 59 



thin film. These and other experiments, which he 

 made with fine lycopodium powder dusted on the 

 surface of the water, into the middle of which he 

 introduced alcohol gently from a fine tube, were 

 very simple, and can easily be repeated. Certain 

 curious return currents which he showed by means 

 of the powder on the surface, he stated he had not 

 yet been able fully to explain. He referred to 

 very interesting phenomena previously observed 

 by Mr. Varley, and described in the fiftieth volume 

 of the Transactions of the Society of Arts, and he 

 believed that many or all of these would prove to 

 be explicable according to the principles he had 

 now proposed. 



APPENDIX B. 



NOTE ON GRAVITY AND COHESION. 



[A paper read before the Royal Society of Edinburgh and 

 published in Proc. R. S. E. April 21, 1862.] 



THE view, founded on Boscovich's theory, com- 

 monly taken of cohesion, whether of solids or 

 liquids, is, that it results from a force of attrac- 

 tion between the particles of matter, which 

 increases much more rapidly than according to 



