j20 Dr. Pearson’s Experiments and Obfervations 
found changed into an entire very hard white folid, receiving 
its figure from the veffel, and weighed 95 grains. On break- 
ing this hard 'folid, the lower part of it feemed to be vitrified, 
or ia a (late of enamel ; and being powdered, it afforded a much 
whiter powder, and of greater fpecific gravity, than before. The 
degree of fire denoted by Wedgwood’s pyrometer was 166 0 . 
Thefe experiments indicated the prefence of a metallic calx, 
a part at lead of which was that of antimony, mixed with 
earthy matter. 
Experiments with different menjlrua applied to James’s Powder. 
I. With water. 
300 grains of this powder were digefted for feveral hours in 
twenty-feven ounces of aiftilled water, and then boiled for one 
hour. While boiling the water appeared milky ; but in half a 
minute’s time, after withdrawing the lamp over which it boiled, 
the liquid became nearly clear, and the fediment depofited was 
apparently the powder undiminilhed in quantity, and in other 
refpeds unaltered. While hot the liquid was decanted upon a 
filter of feveral folds of paper previoufly weighed, through 
which twenty ounces of quite clear liquid, like water, readily 
paffed. Very little powder could be perceived on the filter ; 
but when it was well dried, it weighed fourteen grains more 
than before the experiment. The filtered liquor was taftelefs. 
In about three quarters of an hour it grew (lightly turbid , and 
in ten minutes after became milky. On (landing eight days 
longer, the milkinefs dimini(hed, and a frriall quantity, per- 
haps four grains, of clofe white fediment, firmly adhering to the 
Tides of the veffel, were depofited. A little of this (lightly 
milky fluid being made hot, it grew quite clear, and on cooling 
_ turned 
