2^2 Mr. Macie’s Account of 
grew tranfparent, juft as it would have done, had it not been 
ignited. 
(B) 6.4 gr. of this fubftance, made red hot in a crucible, 
were found, upon being weighed as foon as cold, to have loft 
two-tenths of a grain. This lofs appears to have arifen merely 
from the expulfion of interpofed moifture ; for thefe heated 
pieces, on being expofed to the air for fome days, recovered 
ex a £11 y their former weight. 
(Cjj A bit of this fubftance was put into an earthen cruci- 
ble, furrounded with fand, and kept red hot for fome time; 
when cold, it was ftili white, both exteriorly and interiorly. 
(D) Thrown into fome melted red hot nitre, this fubftance 
did not produce any deflagration, or feem to fuffer any alte- 
ration. 
(E) A bit expofed on charcoal to the flame of the blow-pipe 
did not decrepitate or change colour ; when firft heated it 
diffufed a pleafant fmell ; then contracted very confiderably in 
bulk, and became tranfparent ; but on continuing the heat it 
again grew white and opaque, but feemed not to (hew any 
inclination to melt per fe. Poffibly, however, it may fuffer 
fuch a femi-fufion, or foftening of the whole mafs, as takes 
place in clay when expofed to an intenfe heat ; for when the 
bit ufed happened to have cracks, it feparated during its con- 
tra&ion, at thefe cracks, and the parts receded from each other 
without falling afunder. 
If, while the bit of Tabafheer was expofed to the flame, 
any of the allies of the coal fell upon it, it inftantly 
melted, and fmall very fluid bubbles were produced. That the 
opacity which this fubftance acquires on continuing to heat it 
after it is become tranfparent, is not owing to the fufion of its 
4 furface 
