662 
PROFESSOR W. RAMSAY AND DR. J. SHIELDS ON THE 
It should be remarked that we have confined our criticism to the rectilinear part 
of our work, and have not unfairly taxed the powers of Eotvos’s equation in covering 
those parts of the observations where they approach the critical temperature and are 
represented by a curve. At best, Eotvos’s reasoning leads only to a rough simi¬ 
larity, not to numerical identity. 
Measurements of the surface-tension of ethyl oxide have recently been made bv 
N, P. Kasterin, by a method which, from the figures and diagrams which he 
gives, evidently does not lead to trustworthy results. (‘ Jour. Puss. Phjvs. Chem. 
Soc.,’ 24, Phys. Sect., p. 196.) De Vries, also, in an inaugural dissertation 
(Amsterdam, 1893), has obtained results with ether, which, although confirmatory of 
ours, are not sufficiently numerous to admit of any general conclusion. 
7. Experimental Details, 
It was necessary during the experiments on this subject to maintain the liquids 
investigated at constant temperatures, differing from each other by known amounts, 
and, when the temperatures were high, under considerable pressures. In order to 
Fig-. 2. 
satisfy these conditions, the apparatus consisted essentially of three parts, a tube for 
observing the phenomena, a heating apparatus, and a pressure apparatus. 
The liquid under experiment was enclosed air-free in a piece of thick walled 
barometer-tubing, T, secured in a’ neck N by means of an india-rubber joint com- 
