RESEARCHES ON THE ATTAINMENT OF VERY 

 LOW TEMPERATURES.* 



BY MORRIS W. TRAVERS, D.SC, 



ASSISTANT PROFESSOR OF CHEMISTRY, AND FELLOW OF UNIVERSITY 

 COLLEGE, LONDON, ENGLAND. 



PART I. 



I. Introduction. 



The following is an account of a series of experiments which 

 originated in the year 1900 in an attempt to obtain a small quantity of 

 liquid hydrogen, to be used in separating the gas neon from helium and 

 argon, with which neon is associated in atmospheric air. Sir William 

 Ramsay and I had, at that time, succeeded in separating the gases 

 argon, krypton and xenon from one another, by condensing mix- 

 tures containing them in bulbs cooled in liquid air, and submitting 

 the solid or liquid to fractional distillation. This method could not, 

 however, be applied to the separation of neon ; for, as subsequent ex- 

 periment has proved, the critical point of this gas lies below 65° abs., 

 and consequently it could not be condensed at the temperature of 

 liquid air. It was obvious that rmless liquid hydrogen could be ob- 

 tained, and applied to the separation of the neon from its companions, 

 it would be impossible to obtain the gas in a pure state, and the work 

 on the inactive gases would remain incomplete. 



Experiments on the liquefaction of hydrogen were commenced in 

 March, 1900. After some six or eight failures, mainly the results of 

 attempts to adapt an old air liquefier to the new purpose, I devised and 

 constructed an apparatus with which I was able to obtain the neces- 

 sary quantity of liquid. The work was brought to a successful con- 

 clusion on July 6 of that year, and the separation of the pure neon 

 was effected. 



During the years 1901 and 1902 I was engaged, with the assistance 

 of Mr. George Senter and Dr. Adrien Jaquerod, in making accurate 

 measurements of the pressure-coefficients of hydrogen and helium, and 

 in comparing the constant-volume hydrogen and helium thermometers 

 over wide ranges of temperature. This investigation involved the 

 measurement of the vapor-pressures of liquid oxygen and of liquid 



* The researches described by Doctor Travers were carried on with the aid 

 of a grant from the Hodgkins Fund of the Smithsonian Institution. It is ex- 

 pected that further researches by Doctor Travers will be published as Part II. 



