Experiments and Ohfervations. 
79 
TO DR® BLAGDEN, SEC® R» S. 
sir, Windfor, January 9, 1^86. 
I HAVE made the experiment which you recommended 
me to try, relating to the magnetifm of brafs ; viz. I mixed, 
by means of the blow-pipe, a fmall quantity of iron, with 
about four times its weight of fuch brafs as would not become 
magnetic by hammering. The whole globule weighed about 
two grains, and it attracted the magnetic needle very power- 
fully. I then melted this globule of brafs and iron with about 
fifty grains of the fame fort of brafs as had been ufed before® 
After cooling, the whole lump of brafs appeared to have very 
little power upon the magnetic needle, every part of its furface 
attracting one end of the fufpended needle, fo as to let it juft 
adhere to it when the air was not at all difturbed. But this 
weak and hardly perceivable degree of magnetifm was not in- 
creafed by hammering, nor annihilated by foftening. 
In the courfe of my experiments on the magnetifm of brafs, 
I have twice obferved the following remarkable circumftance. 
A piece of brafs, which had the property of becoming mag- 
netic by hammering, and of lofing the magnetifm by foftening, 
having been left in the fire till it was partially melted, I found, 
upon trial, that it had loft the property of becoming magnetic 
by hammering ; but having been afterwards fairly melted in a 
crucible, it thereby acquired the property it had originally, 
viz . that of becoming magnetic by hammering. 
I have 
