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Sir Ifaac Newton carried two Thermometers , pro- 
perly prepared, out of a cold place into a warm one, 
in order to fhew that the warmth was conveyed 
through the vacuum , by the vibrations of a much 
fubtiler medium than the air : and had thefe laft ex- 
periments upon the Tourmalin at that time been 
known to him, he mull have been agreeably furprifed 
to find them tending fo ftrongly to efiablifh the ex- 
i fiance of that fubtile medium This dodrine re- 
ceives a further confirmation from the experiments 
that follow. 
EXPERIMENT VI. 
About the middle of this month, December, the 
wind being full fouth, and the air loaded with a thick 
fogg, which you know is the worft of weather for 
eledric experiments, thd Tourmalin afforded the fame 
appearances as before, by removing it from one room to 
another j and even into the open vapourous air j not- 
withftanding the unfavourable feafon : but then, the 
appearances were weaker. 
EXPERIMENT VII. 
In the mofi wet feafon, and during frequent heavy 
fhowers of rain, I repeated the firft, fecond, third, and 
fourth experiments. And though the eledric power 
was not very firong, yet they always fucceeded fo well 
as to afcertain the fads. 
* See Newton, Opt. page, 323. 
EX- 
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