[ 323 ] 
Exp. ii. To anfwer this purpofe befl, I feparated 
the Tourmalin from the wax, and placed it in boil- 
ing water for a. fhort time, where it was furrounded 
on all fides with a conductor and an equal degree of 
heat : then, taking it out of the water, I laid the 
convex fide (after it was dry) upon the flip of wood, 
fupported by wax, to which the pith balls were fuf- 
pended ; but no appearance happened, for the balls 
continued at reft. 
Exp. 12. But when the flone remained on the wood 
a little time longer, the balls feparated to a conlider- 
able diftance, fometimes near two inches ; and re- 
mained fo for more than one minute. 
In this flate they were electrified plus, as appeared 
by their acceding towards amber when it was rubbed 
and brought near them. From the balls being elec- 
trified plus, the flow of the fluid from the plus fide 
of the Tourmalin mud have caufed fome part of the 
wood itlelf to be minus , and the balls plus-, becaufe 
the fame effects happened in Exp. p. Befides, elec- 
trified glafs oppofed to the fame wood produced fimi- 
lar appearances. 
Exp. ij. If, whilfl the flone continued refling 
upon the wood, I brought my finger near the plain 
fide of the Tourmalin , the balls receded farther from, 
each other; and when I repeated the approach, it 
every time affe&ed the balls and made them recede 
a little more, unlefs the Tourmalin was become too 
cold; in which cafe they approached nearer, but flill 
continued to be ele&rified plus. 
In this experiment, the finger did nothing more 
than fupply the flone with the eleCtric fluid, more 
readily than the air itfelf would have done. 
T t 2 Exp. 14. 
