138 EFFECTS of HEAT 
On the 25th, in a fimilar experiment, a heat of 64° was ap- 
plied, without any water within the barrel... The platina. tube; 
(having been contaminated in a former experiment with fome 
fufible metal), melted, and the carbonate retaining its cylin- 
drical fhape, had fallen through it, fo as to touch the piece of 
porcelain which had been placed next to the platina tube... At 
the point of contaét, the two had run together, as a hot iron 
runs when touched by fulphur. The carbonate itfelf was very 
tranfparent, refembling a piece of {now in the act of melting. 
. On the 26th of June, I made an experiment with this car- 
bonate, which afforded a beautiful refult. One grain of wa- 
ter was introduced with great care; yet there was a lofs, of 
6.5 per cent., and the refult has fallen to decay. The pyro- 
meter cael 43°. On the outfide of the platina cylinder, 
and on one of the lids, were feen a fet of globules, like pearls, 
as once before. obtained, denoting perfect fufion. When the 
upper lid was removed, the fubftance was found to have funk 
almoft out of fight, and had aflumed a form not eafily defcri- 
bed. (1 have endeavoured to reprefent it in fig, 31. by anideal 
fection. of the platina-tube and its contents, made through the 
axis of the cylinder)... The powder, firft fhrinking upon itfelf 
in the act of agglutination, had formed a cylindrical rod,.a 
remnant of which (4c) ftood up in the middle of the tube. 
By the continued action of heat, the fummit of the rod (at a) 
had been ,rounded,in fufion, and the mafs being now fof- 
tened, had funk by its weight, and fpread below, fo as to 
mould itfelf in the tube, and fill its lower part completely 
(dfge). At the fame time, the vifcid fluid adhering to the 
fides (at e atid d), while the middle part was finking, had 
been in part left behind, and in part drawn gut into, a thin 
but tapering fhape, united by a curved furface (at 4 and ¢) to, 
the middle rod. When the platina tube was unwrapt, the 
thin edges (at e¢ and d) were preferyed all round, and in a 
ftate 
