a result would be highly interesting, and is the only additional one on the subject I am acquainted with, I am desirous of doing so, as well also to point out the remarkable difference between that result and those which are the subject of this and the other papers referred to. Mr. Perkins informed me that the air upon compression disappeared, and in its place was a small quantity of a fluid, which remained so when the pressure was removed, which had little or no taste, and which did not act on the skin. As far as I could by inquiry make out its nature, it resembled water, but if upon repetition it be found really to be the product of compressed common air, then its fixed nature shews it to be a result of a very different kind to those mentioned above, and necessarily attended by far more important consequences.
IV. ON THE LIQUEFACTION AND SOLIDIFICATION
OF BODIES GENERALLY EXISTING AS GASES.[1]
Received December 19, 1844,—Read January 9, 1845.
THE experiments formerly made on the liquefaction of gases,[2] and the results which from time to time have been added to this branch of knowledge, especially by M. Thilorier,[3] have left a constant desire on my mind to renew the investigation. This, with considerations arising out of the apparent simplicity and unity of the molecular constitution of all bodies when in
