60 
PROFESSOR W. RAMSAY AND DR. S. YOUNG 
To find the weight of ether employed, the graduated tube was jacketed with the 
vapour of alcohol, boiling under atmospheric pressure. For lower temperatures the 
tube was surrounded with flowing water. 
The constants at high temperatures were ascertained by help of the apparatus 
employed in our research on alcohol, which will now be described. 
The body of the apparatus consists of a wrought-iron tube A (fig. 2), firmly fixed in a 
horizontal position by being clamped in a vice. As in Andrews’s apparatus, one end 
is closed by a cap B, through which an iron screw passes, the joint being made t’ght 
by a packing of greased leather in which the screw C works, passing through the 
interior of an india-rubber cork, which closely fits the cap. On screwing on the cap, 
the india-rubber is compressed, so that a very high pressure can be withstood without 
leakage. The iron tube has no opening at the other end, but is provided with three 
vertical branches, D, E, and F, closed in a similar manner by iron caps, through 
which the gauges and the experimental tube pass. The gauge G is intended for 
registering high pressures, and FI for low pressures. To the open end of G is sealed 
a glass reservoir, of known capacity, while H is a plain tube, constricted at one end. 
These, and also the experimental tube, which is also constricted at its open end, dip 
into clean, distilled mercury, filling the iron tube completely. The gauges are 
jacketed by narrow glass tubes, through which water flows ; the temperatime of the 
water was registered by a small thermometer, placed in the stream, immediately after 
passage through the gauges. It was found by experiment that, with a rapid current, 
the temperature did not rise sensibly during its passage. The experimental tube is 
fitted with a jacket J, in the bulb of which a liquid boiled under known pressure 
(‘Chem. Soc. Journ.,’vol. 47,p. 640). The experimental tube passes through a perforated 
india-rubber cork, closing the jacket, and protected from the action of the condensed 
hot liquid by a layer of mercury K. The top of the jacket is furnished with a small 
condenser L, to prevent escape of vapour. The pressure under which the pure liquid 
was boiling was read by means of a gauge and barometer. 
The experimental tube was filled with ether by fitting it, with help of a ring cut 
from india-rubber tube, into the end of the tube A (fig. 3). This tube is bent to an 
obtuse angle, and widened into a bulb at B. On the further side of B there is a 
tight stopcock C. Into the bulb is introduced some pure mercury and a quantity of 
the pure ether, much more than sufficient to fill the experimental tube. By warming 
the experimental tube some air is expelled ; the ether in the bulb is then boiled on 
the surface of the mercury, the stopcock being open. When vapour freely escapes the 
stopcock is closed, and the tube is held in such a manner that ether covers the open 
end of the experimental tube. The latter is again warmed, and the ether, which 
enters on cooling, is boiled. The experimental tube, being at a higher temperature 
than the boiling-point of ether under the reduced pressure, liquid ether, trickling 
down into it, is at once gasified and carries with it all air, and a series of bubbles 
rapidly rises through the ether in the bulb. When it is judged that all air is expelled 
