fame chemical Experiments on Tabafheer. $yt 
maiine acid ; bnt which was difcharged by warm cauftic vege- 
table alkali, and by long ebullition in water. 
Upon thefe bits of Tabafheer, another half ounce of 
diftilled water was poured, and again boiled for about half aiv 
hour. This water alfo on evaporation left a white film on the 
glafs veffel, fimilar to the above. The pieces of Tabafheer 
having been dried, by expofure to the air for feme days in a 
warm room, were found to have loft one-tenth of a grain of 
their weight. 
To afcertain whether the whole of a piece of Tabafheer 
could be diffolved by boiling in water, a little bit of this fub- 
ftance, weighing three-tenths of a grain, was boiled in 36 
ounces of foft water for near five hours confecutively ; but 
being afterwards dried and weighed, it was not diminifhed in 
quantity, nor was it deprived of its tafte. 
With vegetable colours . 
§ III. Some Tabafheer, reduced to fine powder, was boiled 
for a confiderable time in infufions of turnfole, of logwood* 
and of dried red cabbage, but produced not the lead change in 
any one of them. 
At the fire , 
§ IV. (A) A piece of this Tabafheer, thrown into a red hot 
crucible, did not burn or grow black. Kept red hot for fome 
time, it underwent no vifible change ; but when cold, it was 
harder, and had entirely loft its tafte. Put into water it 
C c c 2 grew 
