1 625. J Scientific NoHc£$r-^MfigmtUfiu 151 



A notice was read on Carbonate of Copper, occurring in the 

 Magnesian Limestone at Newton Kyme, near Tadcaster ;. by 

 W. Marshall, Esq. MGS. 



The green carbonate of copper, found by the author in a large 

 quarry of magnesian limestone near Tadcaster, runs through the 

 limestone in thin veins dipping to the west ; the dip of the lime* 

 stone being in the same direction, but at a less angle. At Farn** 

 ham, a small village two miles north-west of Knaresborough, which 

 is also in the magnesian limestone, a considerable quantity of 

 copper was formerly . obtained, and these are the only two 

 instances in which Mr. Marshall has heard of any of the ores of 

 copper having been found in the magnesian limestone. 



Article XII. 

 ,; SCIENTIFIC NOTICES. 



Magnetism. 



\, Queries respecting Animal Magnetism. By a Correspondent^ 

 * in a Letter to Mr. Children. ; 



MY DEAR SIR, ' Camhridgej July \S, IS25. 



Though many experiments, iand some of them of very recent y 

 date, have been made on the ^ymnotus electricus and other V 

 fishes having similar powers, yet I am not aware that it has as 

 yet been ascertained whether, and to what extent, they may be 

 possessed of electromagnetic properties. If this animal electri- 

 city be similar to common electricity, it is to be expected that it 

 will be capable of magnetising a needle inclosed in a spiral, 

 but not of causing deviation in the galvanoscope ; if it resemble 

 galvanism, we may expect both effects. From the experiments 

 made by Mr. Cavendish in reference to the Raia Torpedo, it 

 appears that its electricity was most nearly imitated by that of 

 a large extent of coated surface charged to a very low intensity; 

 that *' the quantity of electricity was extremely great,'' and that 

 "it was gradually transferred from one side to the other." I 

 should, therefore, anticipate from the torpedo, magnetic action ^ 

 resembling that from galvanism ; and by analogy, similar effects 

 may be expected from the Gymnotus electricus, Silurus electri- 

 cus, Tetraodon electricus, and Trichiurus Indicus. 



Should any of your readers have the opportunity to resolve 

 these questions, they will, I hope, consider them sufficiently 

 interesting to deserve their attention. 



•; Believe me, my dear Sir, . . ; ' 



fc Very truly yours, J. C, 



