CHEMISTRY: F. E. BARTELL 
Proc. N. a. S. 
indicates the direction of the superimposed effect tending to produce 
abnormal osmose. With electrical orientations represented in cases 
I, II, III, IV and VII, normal osmose would be obtained; with electrical 
orientations represented in cases V and IX, abnormally great positive os- 
mose would be obtained; with electrical orientations represented in cases 
VI and VIII, abnormally small (or negative) osmose would result. 
An indication of the orientation of the electrical charge, and the magni- 
tude of the charge, on the capillary wall system has been obtained by re- 
ducing the material of the membrane to the form of a fine suspension and 
then determining the electrical sign of these particles by cataphoresis, 
i. e., by noting the direction of movement of the fine particles when sub- 
jected to the driving force of a difference of potential. 
IE 
III 
o 
+ 1 + 
+ 1 It 
+ 
Ml 
□ Oi!l 
O 
3x: 
0:IQ a:llO OHIO 
o + - 
The'^difference in potential between the two solutions bathing the faces 
of the^membrane has been measured in practically all our osmotic ex- 
periments. This value has been assumed to represent the difference in 
potential which exists between the two faces of the membrane and to 
indicate at least the direction of the driving force tending to produce 
abnormal osmose. 
It has been noted that the value of the electromotive force observed is 
quite different from the value calculated by assuming it to be due to con- 
tact potential. In some cases it is even opposite in sign to such calculated 
values. 
In the following tables, the sign preceding the potential value refers to 
the sign of the charge on the solution side of the membrane. The ( — ) 
