68 ENDOSMOSE. L.ECT. III. 



Class 3. Bladder of the Ox. In the last place, we pass 

 to the exposition of what we have observed when employ- 

 ing for the interposed membrane, the mucous lining of the 

 bladder of the ox, in the fresh state, and deprived of the 

 muscular layers, as in the case of the stomachs. When 

 this membrane was employed, and a solution of sugar intro- 

 duced into the interior of the two endosmometers, the height 

 which the liquids attained in the tubes was, when the in- 

 ternal surface of the membrane was in contact with the 

 saccharine liquid, 80, and even 113, millimetres in the 

 space of two hours ; but it was only 63, or 72, millimetres 

 when the position of the membrane was reversed. The 

 current of endosmose, therefore, is promoted in this instance 

 from the external to the internal surface of the membrane. 

 The contrary effect is obtained with a solution of gum Ara- 

 bic. The elevation is 18, and sometimes only 7, millime- 

 tres, when the internal surface is turned towards the interior 

 of the instrument containing the gum solution; whereas, 

 when the membrane is arranged the reverse way, the ele- 

 vation is 52 millimetres, or, in some cases, 20 millimetres. 



With the solution of gum Arabic, we sometimes saw the 

 liquid first fall in both tubes, and after a certain time, rise 

 to heights which are pretty nearly the same as those observed 

 with a solution of sugar. In one case the liquid fell in both 

 instruments 7 millimetres during the first hour ; after that 

 time it began to rise again ; and three hours later the ele- 

 vation was 12 millimetres in the endosmometer where the 

 internal surface of the membrane was in contact with the 

 solution of gum, and 8 millimetres in the endosmometer 

 where this surface was in contact with the water. With an 

 albuminous solution and pure water, endosmose does not 

 take place through the mucous membrane of the bladder of 

 the ox in a fresh state : the liquid falls in both the tubes, 

 whether the interior of the instrument contains the albumin- 



