236 Wisconsin Academy of Sciences , Arts and Letters. 
38) The inner liquid Consisted of a normal solution of 
naphthalene in pyridine, the outer liquid was pyridine and the 
membrane rubber. Practically no change in level occurred, but 
large quantities of naphthalene passed into the pyridine with¬ 
out. 
39) The inner liquid was a normal solution of camphor 
in pyridine, the outer pyridine and the septum rubber. Prac¬ 
tically no change in level occurred, but considerable amounts 
of camphor appeared in the outer liquid. 
40) The inner liquid was a saturated solution of camphor 
in 99.5 per cent alcohol, the outer liquid 99.5 per cent alcohol 
and the septum rubber. After half an hour a slight lower¬ 
ing of the level of the liquid in the osmometer was noticed; 
it continued to go down for 3 days, when the experiment was 
stopped. Much camphor had passed into the alcohol without. 
41) The inner liquid was a saturated solution of camphor 
in toluene, the outer liquid toluene and the membrane rubber. 
The liquid at once rose rapidly in the osmometer. In 9 hours 
it reached a height of 32 cm. It continued to rise for three 
days, the duration of the experiment. Large quantities of 
camphor had passed through the septum into the outer toluene.. 
Camphor is very soluble in toluene. 
That naphthalene and camphor should pass through rubber 
was to have been expected, Nos. 38 to 41, since these substances 
are very soluble in hydrocarbons. In No. 40 the main current 
is from the solution of camphor in alcohol to the alcohol; while 
in 41 the main current is from the toluene to the camphor 
solution in toluene. This occasions no surprise when it is 
borne in mind that toluene is imbibed much more rapidly and 
more copiously by rubber than is alcohol,, and that an alcoholic 
solution of camphor is imbibed by rubber more rapidly than 
is alcohol. Again, remembering that it is the relative rate of 
inflow and outflow which determines whether the bulk of the 
liquid in the osmotic cell will change or not under given 
conditions, the results in 38 and 39 are readily explained. 
42) In the osmometer was placed a solid block of camphor 
in form of a cube which weighed two grams; the outer liquid 
was 99.5 per cent alcohol, and the membrane rubber. The os- 
