Physical constants at low temperatures. (1)—The densities of solid oxygen, nitrogen, hydrogen, etc.

Abstract 1. The following experiments on the solid densities of oxygen, nitrogen and hydrogen were carried out as part of a former investiga­tion dealing with gaseous densities at low temperatures. The method adopted was to measure the volumes of the gases sucked into a cooled space of known capacity, when the temperature was such as in the first place to induce liquefaction and finally solidification. For such experiments to be successful the rate of liquefaction and the cooling must be under thorough control, otherwise the cooled space may not get completely filled with solid. Further, the volume of gas condensed ought to be as large as possible, in any case about 20 litres, in order to diminish errors inseparable from the mode of manipulation.