Dr. ingenhousz on Air . 265 
them could absolutely not be rubbed afunder between 
the fingers. The infide of the tube exhibited marks of 
having received impreffions of the melted metal. By 
comparing the Separated particles of this platina with 
particles not expofed to an ele&riCal explofion, they were 
Scarce to be known for the fame fubftance. I had put 
Some iron filings in a tube of the fame Size, and directed 
the fame explofion through it, in order to compare the 
effect of electricity upon it with what happened to the 
platina. I found, by looking at the outfide, Somewhat of 
the Same appearance of being melted. By cutting this 
tube in Small bits, I could eafily pulh out the filings with 
a pin, which I could not do in the other cafe but with 
great force. The filings Buck together, as the particles of 
platina had done; but with lefs force. By this experi- 
ment it Should Seem as if platina (which hitherto could 
never be melted by common fire by itfelf, but only in the 
focus of a very Strong burning glafs, Such as was a little 
while ago made at Paris) were equally fufible, if not more 
So than iron, by ele&rical fire. 1 was Somewhat Surprized 
to find, that the particles of platina taken out of tlieafore- 
Said tube, had got a remarkably Stronger magnetical 
force, being attra&ed by a loadftone at a greater diftance, 
and turning their poles more brifkly upon the water 
than before, though the whole cylinder of thefe parti- 
cles, Still inclofed in the tube, gave no Signs of having ac- 
quired polarity. Thus it appears, that common fire di- 
minishes the magnetical virtue of platina , and that elec- 
trical fire increases it; which I thought the more pro- 
Vol. LXVI. Mm bable, 
