134 EFFECTS of HEAT 
not quite to the brim with a yellowifh-grey fubftance, having 
a fhining furface, with longitudinal ftreaks, as we fometimes fee 
on glafs. This furface was here and there interrupted by lit- 
tle white tufts or protuberances, difpofed irregularly. On 
the ledge of the cup, formed by the ends of the folded plati- 
na, were feveral globular drops like minute pearls, vifible to 
the naked eye, the number of which amounted to fixteen. 
Thefe feem to have been formed by the entire fufion of what 
carbonate happened to lie on the ledge, or had been entangled 
amongft the extremities of the folds, drawing itfelf together, 
and uniting in drops ; as we fee when any fubftance melts un- 
der the blowpipe. This refult is preferved entire, without de- 
ranging the tube. I am forry to find that it has begun to fall 
to decay, in confequence, no doubt, of too great a lofs of its 
carbonic acid. But the globules do not feem as yet to have fuf- 
fered any injury. 
APRIL 25.—The fame fpar was ufed, with two grains of 
water, and a heat of 33°. I have reafon to fufpe@, how- 
ever, that, im this and feveral other experiments made at 
this time, the metal into which the cradle was plunged, on 
firft introduction into the barrel, had been too hot, fo as to 
drive off the water. There was a lofs of 6.4 per cent. The 
refult lay m the cup without any appearance of frothing 
or fwelling.. The furface was of a clean white, but rough, 
having in one corner a fpace fhining like glafs. The cup 
being unwrapt, the fubftance was obtained found and entire : 
where it had moulded itfelf on the platina, it had a fmall de- 
gree of luftre, with the irregular femitranfparency of faline 
marble: when broken, it preferved that character more com- 
pletely than in any refult hitherto obtamed; the fracture be- 
ing very irregular and angular, and fhining with facettes in 
various directions. I much regret that this beautiful fpecimen 
no 
