FOR DIFFERENT LIQUIDS. 51 



bladder unequally, it follows, that in addition to the 

 chemical attraction which the dissimilar particles of 

 the liquids have for each other, a new cause, namely, 

 the stronger attraction of one of them for the sub- 

 stance of the partition, is introduced, which acce- 

 lerates their motion or passage, and must have this 

 effect, that one of them flows out in larger quantity, 

 in the same time, than the other. 



The experiments (Fig. 3) elucidate this process, Mixture is 

 and shew besides, that the exchange of the two determined 

 liquids on both sides of the bladder is essentially equal 61 

 determined by their unequal specific gravities. As theHquids. 

 long as the difference in their composition (which 

 may here be measured by the specific gravity) is 

 very great, the change of volume (increase of one 

 and decrease of the other) takes place rapidly ; but 

 at last, when this difference becomes very small, the 

 liquids mix without further visible change of volume, 

 obviously, because the attraction of the bladder to 

 the mixtures on the opposite sides does not per- 

 ceptibly differ, although the specific gravities are 

 still somewhat unequal. 



In the ultimate result, the action of dissimilar The action 



. of two 



liquids on the substance of animal tissues, in conse- liquids on 

 quence of which their mixture is attended with a tissues 



change of volume, appears to be equivalent to 

 a mechanical pressure, which is stronger from one 

 side than from the other. apposite" 1 



E2 



