A24 Scientific Intelligence. 
(5.) There can be no assumption of a specific magnetism in a sub- 
stance in a general signification as we speak of specific gravity. Co- 
balt is precisely as magnetic as iron, when we use a definite magnetic 
each other by the multiple 24, according as we use a single element or 
great as with the first. For oxygen and bismuth this ratio descends to 
bout 1°9 and 1- This partly explains the fact that while Faraday’s 
estimate of the magnetism of oxygen, with a nearly equal force and 
(7.) Those substances which oppose a lesser resistance to magnetl- 
at pleasure by changing the poles of the electro-magnet when conta! 
in an indifferent glass sphere.. 
In conelusion the author promises us a memoir on the nature of the 
coercive force.—Pogg. Ann., xci, 1, Jan., , 
_ 5. On the laws of the attraction of electro-magnets.—DUB has — 
lished a continuation of his interesting and valuable researches on etl 
netic forces. Before stating however the results of this we 
. : + 
traction, and sustaining power in electro-magnets. By magnetism he 
understands the magnetic excitation of a piece of soft iron by ” ae 
vanic current; Lenz and Jacobi measured this by means of the induced 
