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Proceedings of the Royal Society 
made under the the title “ Are we drying up.’' But it led also to 
a curious hydrostatical question as to the equilibrium arrangement 
of water poured into a shaft already full of air, and supposed to be 
so deep that in its lower parts the air is compressed to a density 
exceeding that of water. This suggested numerous questions, 
such as : What addition to the atmosphere would raise the sea 
from the earth’s surface ? 
Monday , 5 th March 1877. 
Sir WILLIAM THOMSON, President, in the Chair. 
The following Communications were read : — 
1. On the Biliary Secretion with reference to the Action of 
Cholagogues. By Prof. Butherford, F.R.SS. L. & E., 
and M. Yignal. 
(Abstract.) 
Notwithstanding the fact that substances supposed to affect the 
flow of the bile have been administered to man for more than 2000 
years, there is still very great uncertainty as to what does and what 
does not augment the biliary excretion. The indefinite state of 
knowledge regarding this point is due to the circumstance that 
variations in the flow of bile from the human liver are estimated by 
simply observing the colour of the dejections, — a method that is of 
necessity exceedingly rough, for it is impossible thus to detect 
slight variations in the excretion of bile, especially when, as in the 
case of rhubarb, the substance gives to the dejections a colour 
similar to that of the bile, and where, as in the case of sodium 
sulphate, the substance gives rise to copious dejections of a watery 
character, whereby the colour is diluted. 
Even in the case of those substances generally believed to 
augment the biliary flow, e.g., podophylline, observations on man 
have entirely failed to determine whether they merely occasion an 
expulsion of bile from the gall bladder, or an increased secretion 
by the liver. The determination of the point is of great import- 
ance in scientific medicine, for it is calculated to advance our 
