LECT. III. GIZZARD OF THE FOWL. 67 



millimetres only in the second one. In another experiment, 

 after the time mentioned, the elevations were 130 millime- 

 tres and 6 millimetres. 



With the stomachs which we have hitherto employed, 

 endosmose, which is promoted from the internal to the ex- 

 ternal surface of the membrane, always takes place from 

 water to alcohol, as in Dutrochet's experiments. It is re- 

 markable that, with the internal membrane of the gizzard 

 of the fowl, endosmose takes place in the contrary way, 

 namely, from alcohol to water ; and this holds good, what- 

 ever be the position of the membrane with respect to the 

 two liquids. This exception, which we at first attributed 

 to some defect in the membrane employed, we have re- 

 peatedly verified, sometimes by introducing, as usual, the 

 alcohol into the interior of the instrument, in which case we 

 have seen the alcohol fall below the level, and sometimes 

 by placing it externally, when the water constantly mounted 

 in the tube. The influence of the position of the membrane 

 is equally evident in this case. We shall commence by 

 giving the diminutions of height marked in the case where 

 the alcohol was in the interior of the instrument. When 

 the internal surface of the mucous membrane was towards 

 the interior of the endosmometer, the diminution of the height 

 of the alcohol was from 24 to 28, and even more than this, 

 in the space of six hours, whilst it was only 11 and 12 mil- 

 limetres in the other position. In another experiment, 

 which we have selected out of a very large number, the 

 pure water being placed in the interior of the instrument, 

 the elevation was 32 millimetres when the external surface 

 of the membrane was towards the interior of the endosmo- 

 meter, and 16 millimetres in the other position, in about 

 the space of three hours. Consequently endosmose between 

 alcohol is promoted from the internal surface to the external 

 surface of the gizzard of the fowl. 



