312 CHAPTER 50. 
SON, were alike fortunate, about the fame 
time. It is eafy to fee the extreme utiUty 
of this difcovery in conducting all fubfe- 
quent experiments. It foon led to what 
he called the circulation of the eledric 
matter/' 
Belides thefe valuable difcoveries, the 
Hiftorlan of Electricity informs us, that 
Mr. Watson firft obferved the different 
colour of the fpark, as drawn from diffe- 
rent bodies ; that electricity fuffered no re- 
fradtion in paffing through glafs ; that the . 
power of electricity was not afFeCted by the 
prefence or abfence of fire, fmce the fparks 
were equally ftrong from a freezing mix-^ 
ture, as from red hot iron ; that flame and 
fmoke were conductors of eleCtricity ; and 
that the ftroke was, as the points of contaCl 
of the non~eleCtrics on the outfide of the 
glafs. This inveftigation led to the coat- 
ing of phials, in order to increafe the power 
of accumulation; and qualified him emi- 
nently to be the principal aftor in thofe 
famous experiments, which were made on 
the T'harmsy and at Shooter s Hilly in the 
3 y^^r^ 
