Experiments and Obfervations . y% 
filver, a little copper, and a lefs quantity of gold, either be- 
fore or after hammering, had not the leaf! a&ion on the mag- 
netic needle. 
Platina was the metal. I laft examined, and the experiments 
made with it feem to deferve particular attention. 
EXPERIMENT I. 
A large piece of platina, which, after being precipitated from its 
folution in aqua regia , had been fufed, or rather concreted toge- 
ther, being prefented to the fufpended magnetic needle, fhewed 
not the leaft fign of magnetifm. It was then hammered ; but 
after the third or fourth ftroke of the hammer it broke into 
many pieces, feveral of which being tried, Ihewed no magnetifm, 
nor could -any of the fineft particles be attradled by the magnet 
prefented very nearly over them. The broken furface of this 
piece of platina was full of cavities, fome of which were large, 
and others juft difcernible ; and altogether the metal feemed to 
have undergone an imperfect fufion. 
EXPERIMENT II. 
The grains of native platina were examined next, by put- 
ting a magnet juft over them; but the magnet attracted not 
above ten or twenty particles out of about half an ounce of 
platina : and thofe which were attracted had either little or no 
fhining metallic appearance like the reft, and were exceedingly 
fmall. 
EXPERIMENT III. 
Having picked out feveral of the largeft grains of pla- 
tina, I prefented the magnet to them; but they were not 
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