MAGNETIC CHARACTERS OF METALS, &c. 663 
55. The neutralization of magnetism in iron by 
alloying it with zine is a fact of high importance 
in the contemplation of metallic magnetism: and 
especially the magnetism of brass, and other 
alloys, in which zine forms a considerable pro- 
portion. For it is highly probable, that since 
zinc smothers the magnetic influence of large 
proportions of iron, a considerable quantity of 
the latter metal might enter the composition of 
brass, without rendering it palpably magnetic. 
Such in fact, would absolutely be the case, pro- 
vided the alloy were perfect, and that the copper 
had no influence on the magnetic condition of the 
combined iron and zinc. 
56. To satisfy myself on this point, I have 
subjected to chemical analysis, some of those 
specimens of brass which had been found to be 
highly magnetic: and, as far as I have proceeded, 
there appears no reason to suppose that the 
magnetic powers they displayed were due to iron 
in their composition. Indeed, I am now inclined 
to embrace the opinion of Cavallo: (6, note) that 
the magnetism of brass is not due to ferruginous 
matter : but depends upon a suitable arrangement 
of the particles of its proper constituent metals, 
copper and zinc. Nor do I believe that brass 
