Mn Cayallo's Magnetkal 
1 % 
EXPERIMENT IV. 
A hole, fimilar to that mentioned in the fecond experiment, 
was drilled into a piece of brafs that would not become mag- 
netic by hammering, and into it was put fome black calx of 
iron, which was fo far phlogifticated as to be attractable by the 
magnet, and the hole was clofed by a few ftrokes of the ham- 
mer. In confequence of which the piece of brafs, when pre- 
ferred to the fufpended magnetic needle, would attraCt it only 
about that place where the magnetic calx was contained. This 
attraction was very weak. Then the piece of brafs, thus pre- 
pared, was put into the fire, and was kept for about fix minutes, 
in a heat very little fhort of that neceffary to melt brafs, and 
after cooling I prefented it to the needle, expecting that the 
fire might have dephlogifticated that calx of iron fo far as not 
to let it aCt any longer upon the needle ; but the attraction 
appeared to be of the fame degree it was before the heating. 
It feems, therefore, to be demonftrated, as far as the fub- 
jeft will admit of demonftration, that the magnetifm acquired 
by brafs, when hammered, is not owing to iron contained in 
it ; and, confequently, that magnetifm , or the pozver of being 
attracted by, and attradiing , the magnet , may exifi independent of 
iron ; 
TO 
