214 Wisconsin Academy of Sciences, Arts and Letters. 
stand, there will eventually be but two layers A' and B', Fig. 2. 
An examination of A' shows that it consists of chloroform and 
B 
Fig. 1. 
ether saturated with water, whereas the layer B' consists of 
water saturated with ether and chloroform. In the change 
which has taken place, one layer, that of the ether, has gradu¬ 
ally disappeared, and the lower layer has greatly increased in 
bulk and lifted the aqueous layer to the top. The explanation 
of this phenomenon is evident. Ether dissolves very readily in 
chloroform, but in water it dissolves much less readily; again, 
chloroform and water hardly dissolve each other at all. In the 
arrangement we have in Fig. 1, the aqueous layer B dissolves 
ether, and in turn the ethereal layer C takes up some water. 
When the ether has gone into B until it touches the chloroform 
layer A, the latter extracts ether from the aqueous layer B. 
Thus the upper part of the chloroform layer A becomes enriched 
with ether, whereas the lower part of the aqueous layer B be¬ 
comes depleted in ether. The latter depletion is made good by 
a continuous supply of ether from the upper parts of B, which 
are in turn supplied with ether from C. Again, the ether in 
the upper layers of A gradually diffuses into the more distant 
parts of A. This process of the transportation of the ether in 
C through B into A proceeds, then, until the supply in C is ex- 
