OXYGEN LIQUEFIED

Globe, Volume IX, Issue 1244, 2 March 1878, Page 3

OXYGEN LIQUEFIED

The “ Journal do Geneve ” gives an interesting account of one of the most important scientific achievements of modern times in the field of chemistry, which has just been accomplished by M. Raoul Pictet, of Geneva. This chemist has succeeded in liquefying oxygen gas. The paper to which we have referred gives the following sketch of the means employed. By a double circulation of sulphurous and carbonic acids the latter gas was liquefied at a temperature of 65deg. (centigrade), under a pressure of from four to six atmospheres. The liquefied carbonic acid is conducted into a tube four metres long. Two pumps pro duce a barometric vacuum above this acid, which is solidified in consequence of the difference of pressure. In the interior of this tube, containing, as has just been said, solidified carbonic acid, is passed a tube of smaller diameter, in which circulates a current of oxygen, produced in a generator containing chlorate of potash, globular in form, and having walls thick enough to avoid all danger of explosion. The pressure might thug be carried up to eight hundred atmospheres. Yesterday morning, all the apparatus being disposed of as wo have just indicated, and under a pressure which did not exceed three hundred atmospheres a liquid jet of oxygen spouted from the end of the tube at the moment when the compressed and chilled gas passed from this high pressure to the atmospheric pressure. What makes the great scientific interest of this experiment is that it demonstrates experimentally the truth of the mechanical theory of heat, in showing that all gases are vapors capable of passing through the three states—solid, liquid, and gaseous. It is but a fortnight since M. Cailletet succeeded in liquefying the by-oxide of nitrogen, under a pressure of one hundred and forty-six atmospheres, aud at a temperature of lldeg. (centigrade). After the experience of M. Raoul Pictet there remain but two gases that have escaped the proof of liquefaction - hydrogen and nitrogen.