391

Vol. 8.

munday. Feb: 9 1679/80

Present at the Beginning Mr. Astin. Mr Hooke. afterwards Dr. Crone Dr King.
Half an ounce of Refined Siluer (the specifick gravity whereof ^ /to water/ was
found by weight to be as 9 2/3 to one) was melted in a crucible
in a charcole fire in about 1/2 a quarter of an hour. and then an equall
weight of Block tin was thrown into, which immediatly melted like butter
but coold the Siluer but blowing the coles againe the whole masse melted
and incorporated but there seemed a great deal of drosse at the top.
Then we took out the crucible and sufferd it to stand till it was almost cold
then burning vp the crusible upon a sheet of paper a great deale of
powder and Scoria and some peices of metall which though it were soe.
cold as not to burn the paper yet was it soe soft as to temper ^ /& spread/ wth. the
point of a knife like an amalgam of mercury & tin. but breaking
the crusible we found a pretty quantity of metall at the bottom. we picked
out as much as we could of the metall and to make it in a lump we
melted them in another crucible which it presently did & powred it into
water, this lump of metall we weighed and found the spec it
to weigh in the air 173 graines and in the water 157 graines
whence the specifique gravity thereof is 10 13/16 somewhat more then
10 3/4. soe that by the mixture of an equall weight of tin w
whose specifique grauity is but to water is but as 7 to one the siluer
is made about aboue a 10th. part heauier.

Ref: CELL/RS/HF_393  © Centre for Editing Lives and Letters