Method of Making Permanent Artificial Magnets. 335 



Cobalt, 



Iron, 



Arsenic, 



If we assume the trifling unessential commixture of iron to be 

 a substitution for cobalt, then this composition corresponds to the 

 formula Co As^', a combination, which must contain according to 

 estimate 20.74 parts of cobalt and 79.16 of arsenic. 



The name proposed by Scheerer for this mineral, arsenic-co- 

 balt-pyrites, appears to me in other respects little appropriate. 



It is a striking circumstance that neither of these minerals con- 

 tains nickle, which is elsewhere so constant a concomitant of 

 cobalt ; at least, it must have occurred in so minute a quantity 

 as not to be observed in the small portions of the minerals sub- 

 jected to analysis. 



Art. YI. — A New Method of Making Permanent Artificial Mag- 

 nets hy Galvanism ; by J. Lawrence Smith, Student of the 

 Medical College of the State of South Carolina. 



Ever since galvanism has been known to produce magnet- 

 ism especially under certain forms of apparatus, it has been a 

 great desideratum to retain permanently, the great power that 

 is generated within the limits of a few square inches of metal. 



A few years since, having seen what an intense degree of mag- 

 netic force could be generated in a bar of soft iron, by passing 

 galvanic currents around it ; the idea (very natural to most persons 

 witnessing the same experiment) occurred to me, whether this 

 magnetism could not in some manner be retained ; I was aware 

 that so long as soft iron was made the agent it could not ; and if 

 tempered steel was used a difficulty would also present itself, 

 and it was not until about eight or ten months since that the 

 following experiments were put into operation. The object that 

 1 had in view, was to substitute for the iron used in the electro- 

 magnet, red hot steel and cool it suddenly. 



A few feet of copper wire were coiled as shown in the figure, 

 the arrangement being such, that the galvanism in its circuit 

 would generate north and south polarities, at the end of the re- 



