96 



desiccators — model Presenius — we found much smaller decreases, 

 and as we also found a loss of weight when making the experiment 

 differently. A glass bell-jar, in which was hanging a weighing-bottle 

 with gelatine swollen in water, was partly placed in a pail of water, 

 so that the gelaiine remained some cm. above the water surface. 

 There can here be no (piestion of difï'usion to the outside. Yer the 

 adsorption hypothesis is not without its difticidties ; for in taking the 

 above mentioned experiments tli(> desiccator oi- the belljar were lirst 

 well rinsed out and moistened with water, so that one should think 

 the glass surface to l)e entirely covered with a layer of water. 

 Perhaps the two last mentioned causes of decrease of weight are 

 cooperating. 



Whatever may be the cause of decrease, we can distinctly see by this 

 table that both water and swollen gelatine decrease. So if we wished 

 to really confirm von Schi{0EDEr's observation, we first ought to have 

 an arrangement with which water only does not diminish in weight. 



A series of experiments, undertaken in consequence of Foote's 

 communication which has been mentioned before several times, will 

 illustrate how hard it is to make exact observations by the 'statical 

 njethod. In a glass tube were two small tubes filled with water 

 above one another, which had been weighed before. The tube was 

 closed with a rubberstopper or it was sealed in the fiame, and then 

 placed in a thermostat; after two days the tube was opened, and 

 the little tubes were (piickly put in weighing bottles, and were 



weighed. 



TABLE IV. 



48 



48 



.005 



id. id. 



.045 



sealed 



