The differences of temperature arc so grouped together that 
the means of the groups differ from one another by about 
10 ° C. The single drop -weights are correspondingly grouped 
and the mean of each group is then divided by the specific 
gravity of water (0°=1) at the mean temperature of the 
group. 
It appears then that for a range of 20 c C. or 36 ° F. the 
difference in drop-size effected by change of temperature in 
the liquid is inappreciably small, not being more than 
gmm 
0.00277, a quantity almost within the limits of experimental 
error as appears on referring to Table XI ; when the greatest 
di Terence between the numbers for glass, which should be 
gmm 
equal, amounts to 0.00043; or a sixth of the greatest differ- 
ence due to variation in temperature. 
On the whole then we may conclude that the temperature 
takes very little effect upon the drop size in this case. No 
doubt near the point of solidification where liquids have an 
incipient structure, the drop-size would be subject to sudden 
changes of magnitude. A few experiments with other liquids, 
namely turpentol, acetic acid and alcohol showed that with 
them the drop-size was almost equally insensitive to change of 
temperature ; and in all cases as with water the lower the 
temperature on the whole, the larger the drop. 
We have now examined seriatim all the chief causes upon 
which the drop-size depends in the case S L G. They are (1) 
Rate of delivery ; (2) Solids held in solution ; (3) Chemical 
variation of liquid ; (4) Radius of curvature a case of geome- 
trical relation between solid and liquid ; (5) Density and che- 
mical nature of solid ; (6) Temperature. 
Our data are however still insufficient for us to predict un- 
der all circumstances the relative sizes of the drops of liquids 
under known external conditions. Clearly the term we miss 
is closely related to the specific cohesion of the liquid. But 
what is cohesion? and how can it be measured? It lies 
