205 
Turpentol and Air. The turpentol and benzol here employed 
ha'd the specific gravities of 0.863 and 0.86T respectively they 
may therefore be considered of equal density. Hence varia- 
tion in the liquid medium independent of variation in’its den- 
% 
sity produces an enormous effect upon drop-size. We shall 
i 
have occasion to return to this case. 
The influence of the liquid medium on the drop size and 
the share which the specific gravity of the medium has in de- 
termining the drop size will be well seen on comparing the 
drop size of mercury which falls through various liquid 
media. 
The arrangement of the apparatus for this purpose is seen 
in Fig. VIII. As far as A it is similar ts fig. VII. The sy- 
phon A is a capillary tube : its lower end, which is turned 
vertically downwards rests upon a sphere of brass, R which 
has been washed with nitric acid and sodium amalgam and al- 
lowed to soak for some days under mercury. Mercury ad- 
heres perfectly to such a spltere. In every case the sphere 
was immersed just half -way in the liquid. A small capsule 
S was supported in the liquid on a stand T about half an inch 
lower than the bottom of the sphere. As soon as gt became 
constantly 5” the vessel V was moved so that S came under 
R. Five drops of mercury having been caught the cup was 
removed horizontally as before, taken out and replaced by a 
fresh one and so on. The batches of five drops were -washed 
dried and weighed. The results with different liquids are 
given in Table XVI. 
We may here notice with advantage a phenomenon which 
attends the separation of drops under several circumstances 
but which can be watched most narrowly in the cases of SLL, 
because in a liquid the separation of a drop is less abrupt 
than in a gas. 
When water falls from glass through air, immediately after 
the drop separates, a very minute drop is frequently project- 
ed upwards from the upper surface of the drop. I have not 
traced the conditions under which this supplementary drop is 
