920 REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



eiit kind to those mentioned above, and necessarily attended by far more 

 important consequences.". 



It is, to say the least, singular that Faraday was not aware in 1823 

 that any of the gases had been liquefied. This is his own statement, 

 and no one who knows Faraday's character can doubt that he believed 

 what he wrote; but a letter by Faraday claiming the authorship of a 

 paper previously published, over the initial letter of his Christian name, 

 appeared in the very same volume of the Annals of Philosophy referred 

 to above, published in 1823, and which contains the following editorial 

 paragraph : "A paper on the compressibility of water, air, and other 

 fluids, and on the crystallization of liquids, and the liquefaction of aeri- 

 form fluids, by simi)le pressure, was prepared by Mr. Perkins for the 

 purj)ose of submitting it to the Eoyal Society ; but it was accidentally 

 misplaced previously to the last meeting, and, therefore, could not be 

 announced to the society with the other papers. It contained, we are 

 informed, a minute descrii^tion, accompanied with figures, of his com- 

 pressing apparatus ; a diagram, showing the ratio of compressibility of 

 water, beginning at the pressure of 10 atmospheres, and proceeding 

 regularly to that of 2,000 ; and some experiments on the compression of 

 atmospheric air, which appears by them to follow a law varying from 

 that generally assigned to it by philosophers. Mr. Perkins intended to 

 announce also, in this paper, that he had effected the liquefaction of 

 atmospheric air and other gaseous substances, by a pressure equal to 

 that of about 1,100 atmospheres ; and that he had succeeded in crystal- 

 lizing several liquids by simple pressure." In a paper " On the prog- 

 ressive compression of water by high degrees of force with some trials 

 of its effects on other fluids," by J. Perkins, read June 15, 1826, in the 

 Philosophical Transactions for 1826, I find the following: 



"With the same apparatus I also made experiments on the compres- 

 sion of other fluids. The most remarkable result I obtained was with 

 concentrated acetic acid; which, after compression with a force of 1,100 

 atmospheres, was found to be beautifully crystalized, with the exception 

 of about -^ff part of fluid, which, when x)oured out, was only slightly acid. 



"I next applied the apparatus to the compression of teriform fluids. 



" In the course of my experiments on the compression of atmospheric 

 air, by the same apparatus which had been used for compressing water, 

 I observed a curious fact, which induced me to extend the experiment, 

 \'1z : that of the air beginning to disappear at a pressure of 500 atmos- 

 pheres, evidently by partial liquefaction, which is indicated by the quick- 

 silver not settling down to a level with its surface. At an increased 

 X)ressure of 600 atmospheres, the quicksilver was suspended about ^ of 

 the volume up the tube or gasometer; at 800 atmospheres, it remained 

 about ^ up the tube; at 1,000 atmospheres, f up the tube, and small 

 globules of liquid began to form about tlie top of it; at 1,200 atmospheres 

 the quicksilver remained f up the tube, and a beautiful transparent 



