OF THE LATE MB. WILLUM STUEGJ 69 



level by voltaic action. In his experiments, a glass vessel 

 divided into two compartments, by a bladder partition, had 

 one of the partitions filled with water. By sending a voltaic 

 current through the diaphragm the water was carried along 

 with it until nearly the whole of it was driven into the other 

 compartment, Mr. Porrett employed a battery of eighty cells, 

 but Mr. Sturgeon succeeded in obtaining a striking result, of 

 a similar nature, by the use of a simple Daniell's cell, the 

 copper and zinc plates of which were couuected together by a 

 conducting wire; after a few days action the solution of sul- 

 phate of copper was found to be four inches higher than the 

 level of the liquid in contact with the zinc plate. Xhere is 

 some reason to believe, that in Mr. Sturgeon's experiment, 

 the ordinary phenomenon of endosmose and exosmose, so ably 

 discussed by Professor Graham, had some place. Indeed, 

 Mr. Porrett's experiment is, probably, only a peculiar in- 

 stance of the mutual action of two dissimilar fluids in a porous 

 material, the one fluid positively electrified, and the other 

 negatively electrified water. 



In investigating the action of heat on the poles of a 

 magnet, Mr. Sturgeon found that an alteration of attraction 

 for a suspended needle was thereby produced, which altera- 

 tion subsided to a considerable extent as the magnet became 

 restored to its original temperature. Mr. Sturgeon drew 

 from his observations the conclusion that the magnetic poles 

 move from the point where the heat is applied. Subse- 

 quently, on repeating the experiment by which Barlow found 

 that the magnetic virtue of iron disappeared at a white heat, 

 he found that a full red heat was capable of effecting the 

 same result. Hjs paper, entitled " Some Peculiarities in the 

 Magnetism of Ferruginous Bodies," published in the seventh 

 volume of the Society's Memoirs, contains an able discussion 

 of this interesting subject ; results of a very striking charac- 

 ter being obtained with bars magnetized either by electric 

 currents or the inductive action of the earth. Mr. Sturgeon 



