[ 775 ] 
were not mixed * ; yet thefe I have given the mag* 
netic virtue to, when they had it not ; and fome pieces 
of brafs, which naturally attrad the needle, feem to 
the eye as fine a bright yellow as any other, and are 
as malleable as any I ever met with. 
Pieces of brafs without any magnetic power, by 
properly hammering and giving them the double 
touch, after Mr. Mitchel’s method, I have made at- 
tract and repel the needle, as a magnet does, having 
two regular poles : and I now fend you one fuch piece 
of brafs, which I have thus made magnetical. You 
will alfo receive a couple of needles, which I made 
myfelf after the late Zachary Williams’s method, and 
a little Hand whereon to place them, the better to 
fhew how this magnetic bar attracts and repels the 
needle when properly applied ; for it mud be noted, 
that in making thefe experiments it is neceiTary to em- 
ploy a very good needle, about 3* inches long, well 
and tenderly fet, and not covered with glafs. 
1l ou will obferve, when you try this bar, that the 
fame poles repel each other, and the contrary poles 
attract ; which proves this piece of brafs to be indued 
with true magnetic virtue and polarity. However it 
mud be noted, that though the fame poles repel each 
other, yet, like natural magnets, in contact, or near- 
ly fo, they attract each other ; therefore when you 
would fhew the repelling power of this brals bar, you 
mud not bring it nearer the needle than T 2 - of an inch. 
Magnetic brafs does not attrad iron, not even the 
lead particle, fo far as I can find : whether this is 
* This refers to Mr. Baker’s having fuppofed, that old iron 
and old brafs may be mixt fometimes, and melted down together. 
owing 
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