— m — 
persistent und stubborn cohesions respectively, increase in 
the former two tends to diminish the drop size — increase in 
the last, to diminish it. Let us examine in like manner the 
influence of the similar properties of the medium : — 
(1.) The density of the medium. Increase in the density 
of the medium is equivalent to diminution in the density of 
the dropping liquid and must therefore be followed by a ten- 
dency to increase in the drop -size. 
(2.) Stubborn cohesion of medium. The resistance to dis- 
placement or stubborn cohesion of the medium tends to keep 
back the drop in its place and makes it necessary for a larger 
quantity of the dropping liquid to accumulate, that is, it in- 
creases the drop-size. 
(3.) Retentive cohesion of medium. The same force of 
persistent or retentive cohesion which causes the drop of a 
liquid to take the spherical form, would also cause the liquid to 
give or tend to give a spherical form to an irregularly shaped 
volume of a solid, liquid, gas or vacuum in it. Thus gas- 
bubbles, in liquids have an approximalv spherical form not 
by reason of the cohesion of the parts of the gas, but from 
the cohesion of the medium which moulds the gas into that 
form by which the cohesion of the liquids is most gratified. 
Hence increase in the retentive or persistent cohesion of the 
medium tends to diminish the dropsizc of the dropping liquid. 
In all cases of SLL, we may represent the direction the 
determinants by the following scheme, in which the sign -f 
denotes a tendency to increase, the sign — a tendency to 
diminish the drop size. 
SLL. 
DRorn.NG 
+ ! 
Stubborn cohesion. 
.MEDIUM 
4 * 
Stubborn cohesion. 
Density. 
LIQUID. 
Persistent cohesion. 
Density. 
LIQUID. 
Persistent cohesion. 
