LECT. III. APPARATUS. 51 



midst of another liquid, may act on the outer one, receive 

 the surrounding liquor, and reject the one it had previously 

 contained, by operating in a manner analogous to endos- 

 mose. 



Matteucd and Cima's Experiments. We must, however, 

 confess that hitherto very few investigations have been 

 undertaken with the view of making such applications of 

 endosmose to physiology as the subject appears to be sus- 

 ceptible of. To do this it was necessary to vary the liquids 

 between which endosmose takes place, and to select the 

 membranes, so that we might always keep as close as pos- 

 sible to the conditions under which the analogies, between 

 this phenomenon and those which exist in the interior of 

 living bodies, have been observed. In conjunction with 

 Professor Cima I undertook this inquiry, and I shall now 

 state the results of our researches. 



Classes of Membranes. -The membranes which we sub- 

 mitted to experiment may be arranged in three classes; the 

 first including the skin of the frog, the torpedo, and the eel ; 

 the second, the stomach of the lamb, the cat, and the dog, 

 and the gizzard of the fowl ; and the third, the bladder of 

 the ox and of the pig. 



Apparatus. -^We shall not stop to describe our apparatus, 

 as it differed in no way from the endosmometer of Dutrochet. 

 But I may observe that in all our experiments we used, at 

 the same time, two endosmometers, the bore of whose tubes 

 was exactly three millimetres [about ath of an English inch] 

 in diameter ; and their scale was divided into millimetres. 

 In a glass vessel, sufficiently large to hold the two instru- 

 ments, we placed a support upon which was firmly fixed a 

 metallic plate perforated with a great number of small aper- 

 tures. Upon this plate we put the two endosmometers ; 

 and in order that they might not be liable to a change of 

 position, we loaded them with a large leaden plate pierced 



