r 52 t 
find no more bubbles produced thereby, than what 
might rationally be fuppofed to be produced from 
lime, and other dirt mixed with the fand.” 
Having thoroughly confidered thefe experiments, 
they appeared to me far from being decifive, and 
that if the Do&or had placed more confidence in the 
power of the magnet, and lels in his menftruums, 
he would rather have concluded that there might be 
fome forts of iron ore which his menftruums would not 
touch in the moift way, nor any regulus be produced 
from them in the dry, as he made ufe of them, which 
yet might, under fome other hands, be fubdued, by 
more apt and powerful methods than any which at 
that time he was acquainted with. 
However I apprehended I might fairly draw this 
conclufion from his experiments, viz. that the fand 
was not altogether and limply iron, but that it was 
ftrongly united with a very ftubborn, fixed, and per- 
manent earth, which could not be feparated from it 
without fome extraordinary, as well as powerful 
means j but I could not think this a fufficient objec- 
tion to the profecution of an experiment, which, if 
it fucceeded, might be attended with very happy 
confequences. Proceeding therefore upon this fup- 
pofiticn, I mixt up about 8 or 9 ounces of the fand, 
with a proportional quantity of a ftrong corrofive flux, 
which I put together into a crucible, and committed 
it to a very ftrong fire in an excellent wind-furnace, 
where 1 kept it for between two and three hours, hop- 
ing by this means to have anfwered the intended pur- 
pofe j but I confefs I was not a little furprifed, that, 
after the crucible was taken from tl\e fire, 1 could not 
find 
