342 Dr. Pearson's Experiments and Obfervations 
Having found that this infoluble powder would not melt 
with fulphur when heated red-hoi , I made the following 
experiment. 
(d) Twenty grains of it being mixed with three 
times its weight of fulphur, were put into one of Mr. 
Wedgwood’s crucibles that would contain one ounce- mea- 
fure, which, with a cover well luted on, was put into a three- 
inch Englifh crucible, and calcined bone in powder filled the 
fpace between the two crucibles. After expofing this charge 
to k red heat half an hour, and in a white heat ten minutes, 
the crucibles were cooled; and being opened, the pyrometer 
piece of Wedgwood in the bone afhes was found to indicate 
65°, and the- mixture- in the inner crucible had apparently been 
melted into a refin-like mafs that adhered firmly to the tides of 
the veffel. Twenty-eight grains were fcraped off, which, after 
digeftion and boiling in marine acid, afforded fix grains of 
Algaroth powder. A great deal of hepatic air was difcharged 
during this folution, and very little fulphur was left on the 
filter with the part not diflblved by the marine acid. This 
undifiolved part, which weighed fix grains, was blackifh, tafte- 
lefs, not heavy. It was infufible with the blow-pipe, both 
alone, and mixed with fulphur and tartar ; but with phofphoric 
acid it melted into a blackifh fcoria-like mafs. I could only 
conjecture, that this laft part was antimonial calx, fo far vitri- 
fied with phofphorated lime as to be neither foluble nor redu- 
cible or fufible, except with phofphoric acid. 
( e ) By a fimilar experiment, but with alkali of tartar 
twenty grains, fulphur thirty grains, and ten grains of this 
infoluble part of James’s Powder, a fufed mafs was obtained 
that partially diflolved in water, and afforded kermes mineral 
on pouring an acid into this folution; but a great part was 
infoluble 
