ON ENDOSMOSIS EXAMINED. 45 



molecules are set in motion by an external force, 

 it may always be assumed, that that part of the 

 molecules, which is immediately in contact with the 

 wall of the tube, either is not in motion, or possesses 

 only a small velocity, and the velocity of efflux 

 must be a function of the cohesion, and at all events 

 not dependent on the wall of the tube. 



If now the efflux of the water on one side of the 

 bladder is produced by the attraction of the saline 

 particles for the water, and the efflux of the brine 

 on the other side is produced by the attraction of 

 the aqueous particles for the saline particles, it is 

 impossible to explain how water and brine can 

 move in the same tube with unequal velocity in 

 opposite directions ; the two liquids being supposed 

 to have a mutual attraction, that is, to be miscible. 

 This attraction must act within the tube just as 

 well as without; and we might therefore suppose, 

 that when the two liquids have become mixed, the 

 mixture could only move in one direction with a 

 medium velocity. 



Assuming that a mixture is formed in the open 

 orifices of the pores or tubes, or in any part of 

 them, it is difficult to see, why saline particles 

 should not pass from one side to the water, or 

 aqueous particles to the saline ones in the bladder, 

 since the mutual attraction must be regarded as 

 equal on both sides. The chemical affinity of the 

 two liquids does not explain the efflux. 



If we suppose, that in certain pores only brine, 



