PROFESSOR FARADAY ON THE LIQUEFACTION AND SOLIDIFICATION OF GASEOUS BODIES.

New Zealander, Volume 1, Issue 15, 13 September 1845, Page 4

PROFESSOR FARADAY ON THE LIQUEFACTION AND SOLIDIFICATION OF GASEOUS BODIES.

On Friday evening Professor Faraday delivered a most interesting lecture at the Royal Institu tionin A.lbermarle street, out he Liquefaction and Solidification of Gaseous bodies. Before commencjng his lecture, he read an extract from a letter written by Professor Leibig, of Giessen, shortly after his visit to this country, in which the learned wtiter said the thing that stiuck him most in England, was the pei suasion that only those works that bad a practical tendency attracted attention and commanded respect, whilst those which were purely scientific were almost unknown ', and yet the latter were the true sources Horn which the others flowed. In Germany, added Liebig, it was the contrary j but he did not say that that was better— in his opinion the golden medium was the proper course. Mr. Faraday then proceeded with his lecture. The condensation of gases, said he, had been brought before the public some years ago. A. gas was one of those substances in an aei ial form which remained permanent under the ordinary circumstances of temterature and pressure, whilst vapour was like gas, but winch under ordinary circumstances, was condensable again into liquid. It was at one time thought that all gases were perfectly elastic fluids, but by his researches he had succeeded, in turning into vapoui the following nine gases, namely— chlorine, muriatic acid, sulphurous acid, sulphuretted hydrogen, carbonic acid, euchlorine, nitrous oxide, cyanogen, and ammonia. One of these, carbonic acid, the late celebrated Thillourier, af Paris, had after many experiments, obtained in a solid state, and Bonsen bad subsequently obtained also cyanogen in a similar condition. But although continued attempts had been made to solidify the other seven, and b.y immersion in deep water, a pressure of 200 atmospheres, or of 3000lbs, to a square inch, had been produced, still they had been unattended with success. He would explain what he believed to be (he reason of the failure.- If he took a bottle half filled with ether, 'and this wasLatour's experiment) and applied it to heat, the ether would rise in vapour, and so would continue until the vapour was much condensed. At last the liquor below and the vapour above would be of as nearly the same weight as possible, and the least degree of additional heat vi ould turn the liquor into vapour, or if taken away convert the vapour into liquor. Obsei ye what happened. A.t that temperature of ether, no pressure could bring the vnpour into a liquid state ; at a lower temperature it would. He lielieved, the reason why so many had failed in liquifying and solidifying gases was, that although they could procure the immense pi e.>sui c lie bad mentioned, they could not obtain a degree of temperature sufficiently low. He would explain in what manner he had succeeded. He had taken as bis basis, cat bonic acid gas in its solid state, as produced by Thillourier. A quantity of carbonic acid in partly a liquid and partly a vapour state, being confined in a tube, the expansion of the vapour forced the liquid tin ough an orifice in the side, into a cylindrical biass box, and being acted upon by a rapid current of air, the liquid carbonic acid was immediately converted into a solid substance like snow. Its temperature in that state was 70 degrees below Fahrenheit ; but though he took that as his basis, it was not low enough for the put pose of his experiments. The temperatui p,must therefore be further decreased It had been demonstrated by Thillourier, that if ether had been applied to solid carbonic acid, the tempeiature could be reduced to even 105, degiees below Fahrenheit ; but a lower degree was required still, and that was obtained by exhausting the air. His object then was, to combine this extreme degree of cold with great pressure in bis experiments on gajßes. The means by which he effected it he thusdescribod :— A quantity of gas in a glass vessel, was forced by a condensing pump into a tube inserted in the receiver of an air pump? that part of the tube inserted in the receiver was made of common bottle glass, (the strongest kind for experiments, and capable of bearing an enormous pressure), in the shape of a retort, and the bent or lower part of the tube lying immersed in the cold bath, (produced ! by solid carbonic acid, combined with ether, after the air had been exhausted,) gas in a liquid, and by an increased degree of pressure, also in a solid state, could be obtained. The learned professoi illustrated the truth of the principle bv producing defiant gas in a liquid stale, and observed that he had succeeded in obtaining in the same condition phosphoric hydrogen, hyd»iodici acid, hydrobomic acid, fluoboron, and fluosilicon, — and in a solid form, sulphurous acid, sulpha , retted hydrogen, euchlorine, nitrous oxide, hydriodic acid, and hydrobomic acid. He had made carbonic acid the type of the otheis, but he thought that nitrous oxide would give a power of teinpeiatureas far below carbonic acid as that was below common ice. He saw no reason why the same result might not be obtained from oxygen, hydrogen, and nitiogen ; and, in fact, he had hoped that evening to have shown oxjgen in a

liquefied state, but he had failed in his experiments, not because his principle was wrong, but Horn the poious and hence imperfect nature of the vessels used. With respect to hydrogen, he had had indications jn the course of his experiments that it would be found to be a metal of a most subtile nature. The theatre was filled, and the learned Professor' as he deUiled the progress and wonderful results of his researches, was listened l» with Ibe most profound attention.