. II. MOLECULAR ATTRACTION. 33 



give you the theory, which belongs entirely to the domain 

 of the highest mathematical analysis. The experimental 

 results which I have adduced are sufficient to prove that 

 the phenomena depend on that force which we call mole- 

 cular attraction a force which is exerted between the 

 molecules of the solid and those of the liquid, and between 

 those of the liquid itself, and which ceases to act imme- 

 diately the smallest [appreciable] intervals separate the 

 molecules. 



To avoid any false application of the phenomena of ca- 

 pillary attraction to the animal economy, it must be con- 

 stantly borne in mind that a space completely filled with 

 liquid is incapable of exercising any capillary influence ; 

 that the action of a capillary tube on liquids is due, less to 

 the substance of the tube, than to the nature of the liquid 

 with which its inner surface is moistened, and, finally, that 

 liquids never overflow the upper aperture of the tubes in 

 which they are elevated, by the mere agency of capillarity. 



Imbibition. The phenomena of Imbibition, of Hygros- 

 copicity, Sac. are generally of the same nature as the pre- 

 ceding, and depend on the same force. A piece of sugar, 

 a wick of cotton, and a cylinder of sand, of ashes, or of 

 sawdust placed in contact with water, or any other liquid 

 which moistens them, immediately draw up the liquid into 

 their whole mass ; that is to say, they imbibe it. It is the 

 same with certain tissues, as cartilages and tendons, which, 

 being dried and then plunged into water, resume in a few 

 hours all the properties they possessed during life. This 

 effect is the result of the action of the absorbed water. So 

 also in the celebrated experiments with the rotifera, which 

 are restored to life and motion when moistened by a drop 

 of water. 



The phenomena of imbibition have an influence on the 

 filtration of liquids. For when these hold in suspension 

 3 



