CHAP. XXVI.] MECHANISM OF ABSORPTION. 285 



ether, oil, albumen, gum and sugar would disappear from the 

 stomach in very different intervals of time. 



Absorption as influenced by the Porous Solid. An extensive 

 and accurate series of experiments has been recently performed by 

 MM. Matteucci and Cima, in which they investigated the influence 

 of different kinds of animal membranes, and of various arrangements 

 of them, on the transmission of various fluids. They employed 

 1. The skin of the frog, the torpedo, and the eel; 2. The mucous 

 lining of the stomach of the lamb, cat, and dog, and of the gizzard 

 of the fowl : and, 3. The mucous lining of the bladder of the ox 

 and pig. The following are the general conclusions derived from 

 these experiments, in the words of their translator : 



"1st. The membrane interposed between the two liquids is very 

 actively concerned according to its nature, in the intensity and 

 direction of the endosmotic current. 



"2ndly. There is, in general, for each membrane a certain 

 position in which endosmose is most intense; and the cases are 

 very rare in which, with fresh membrane, endosmose takes place 

 equally, whatever be the relative position of the membrane to the 

 t wo iquids. 



" 3rdly. The direction which is most favourable to endosmose 

 through skins, is usually from the internal to the external surface, 

 with the exception of the skin of the frog, in which endosmose, in 

 the single case of water and alcohol, is promoted from the external 

 to the internal surface. 



" 4thly. The direction favourable to endosmose through stomachs 

 and urinary bladders varies with different liquids, much more than 

 through skins. 



" 5thly. The phenomenon of endosmose is intimately connected 

 with the physiological (natural or healthy) condition of the mem- 

 branes. 



"Gthly. With membranes, dried or altered by putrefaction, 

 either we do not observe the usual difference arising from the 

 position of their surfaces, or endosmose no longer takes place."* 



With the mucous lining of the stomach of the lamb (whether the 

 paunch or the true digestive stomach, is not mentioned) these 

 trustworthy experimenters found that water passed through towards 

 a solution of sugar in greater quantity when the water was at 

 first placed on that side of the membrane which is naturally turned 

 towards the interior of the cavity of the stomach, than when it 



* Lectures on the Physical Phenomena of Living Beings. By Carlo Matteucci. 

 Translated under the superintendence of Dr. Pereira. London. 1847. P. 65. 



