80 W. Sturgeon, Esq., on (he 



24. It is generally understood, principally, I believe, upon 

 the authority of Dr Seebeck, of Berlin, that iron becomes 

 *' completely destitute of magnetic action" when alloyed with 

 four times its weight of antimony.* This, however, does not 

 appear to be correct, for I have formed very perfect alloys of 

 these two metals, in a great variety of proportions, and find 

 that when the iron does not form even a twentieth part of 

 the mass, it is still magnetic, though in a very low degree. 

 When the alloy is of equal parts of iron and antimony, it is 

 highly magnetic. This alloy, when broken, exhibits a dark 

 grey fracture, somewhat glittering. It is easily reduced into 

 powder by the operation of a file, or by pounding in a mor- 

 tar ; and what is very remarkable, it yields an abundance of 

 deep crimson sparks when struck against hard steel. 



25. It has already been stated (17), that pure copper is 

 not magnetic ; and I must now add that, in a very few cases 

 only have I detected magnetic action in the copper of com- 

 merce, although I have tested a great number of specimens 

 both in the state of sheet and of wire. 



26. In the copper coinage of this country, I have never 

 yet met with magnetic action, notwithstanding the number 

 of experiments I have made on the various copper coins that 

 have been struck in the reigns of several sovereigns. 



27. In the gold and silver coinage, however, in which cop- 

 per forms a constituent part, the case is very diff'erent. These 

 alloys are nearly all of them decidedly magnetic, and, pro- 

 bably, none of them entirely free from magnetism. The gold 

 coinage, however, displays much feebler magnetic action than 

 the silver coinage ; indeed, in many gold coins the existence 

 of magnetism may be considered as questionable, whilst in 

 others, and especially in those of 1844, magnetic action is 

 prominently displayed. 



28. The silver coinage, although in some specimens scarcely 

 any magnetic action can be detected, is generally magnetic 

 in a very eminent degree ; and I have found that, when any 

 one piece of a particular coinage displays considerable mag- 

 netic action, the whole of that coinage, as far as I have ex- 



* Brewster's Magnetism, p» 102. 



