SS W. sturgeon, Esq., on the 



but feebly magnetic. I have met with a few sovereigns of the 

 present reign which are more magnetic than any others that 

 have come under my notice. 



52. With respect to jewellery, it is generally more highly 

 magnetic than those articles of silver that have come under my 

 examination. Wedding rings, which contain but a small 

 proportion of copper, have so slight a degree of magnetic ac- 

 tion as almost to elude the detection of it ; whilst ornamental 

 rings, keepers, &c., which contain a much greater proportion 

 of copper, are, generally, highly magnetic. Some ear-rings 

 that I have examined, are still more magnetic than the finger- 

 rings. Gold watch-chains are generally magnetic, especially 

 those containing much copper : also gold spectacle frames, 

 unless they be of what is called fine gold, are magnetic to a 

 considerable extent. [In all cases where steel or iron screws 

 or nails have been found in the gold articles examined, those 

 parts have been carefully removed previously to the magnetic 

 test being applied. 



53. We next come to the consideration of metallic alloys, of 

 which either iron or nickel form no inconsiderable propor- 

 tions. It has already been shewn in the first section of this 

 memoir (24), that antimony, when alloyed with iron, counter- 

 acts the magnetic action of the latter metal in a very emi- 

 nent degree, rendering it almost undetectable when the iron 

 amounts to little less than a twentieth part of the mass : and 

 I find that when the ferruginous metal amounts to no more 

 than about one-fortieth of the mass, its magnetic powers en- 

 tirely disappear. 



54. There are several other metals, besides a number of 

 other bodies, which either partially or wholly neutralize the 

 magnetic actions of iron and nickel. The most eminent of the 

 metals in this capacity is zinc. This metal, which till these 

 researches were undertaken, was not known to affect the mag- 

 netism of iron, neutralizes nearly the whole of that power 

 when alloyed with an equal proportion of the ferruginous 

 metal. And, although from an accident with the melting-pot, 

 I have not yet arrived at the fact, I have no doubt whatever 

 that, v/hen the iron amounts to no more than one quarter of 



