[ 3+r ] . 
degree of light, and remained vifible for more than 
two hours after, when even the heat of the hand 
would plainly increafe its light. 
Bolognian phofphorus is faid, by Lemery, and alfo 
by Mulfchenbroek *, to imbibe lefs light when hot 
than when cold, as it appears lefs bright when carried 
into a dark room. But this appearance may be 
caufed by its parting with the light it has received 
faller when in the former date, than when in the 
latter, according to the lad experiment ; as it mud 
lofe more when hot, than when cold, during the time 
of conveying it from the place where it takes the 
light, to a place dark enough to obferve it in. And 
this feems to be the caufe alfo, why Bolognian phof- 
phorus never appears fo bright after it has been 
illuminated, and confequently in fome meafure 
heated, by the dired beams of the Sun, as after it has 
only been expofed, in the diaded open air, to the 
common light of the day. 
Experiment VI. 
i 
The balls ufed in the lad experiment were kept in 
the dark for two days after, and then each at the fame 
time was put into a bafon of boiling water in a dark 
room : that which had parted with its light in the hot 
water before, was not vifible ; but the other appeared 
luminous for a confiderable time. 
When the phofphorus has once lod as much of the 
light it had received, as the heat of boiling water will 
* See his Intro duello ad Pbilofophiam Naturakm, § 1697. 
Sec alfo § 1704 and 1686, 
cauft 
