616 Mr. woulfe’s Experiments to af certain 
filver. Forty-fix grains of artificial horn filver [<2], dif- 
folved in fpirit of hart’s-horn, and dried in the fame flow 
manner, increafed only two grains in weight, and was of 
the fame dark colour; owing, no doubt, to a fmall por- 
tion of volatile fpirit adhering to it. 
The two drams and two lcruples of horn filver, obtained 
by means of the fpirit of hart’s-horn, were well mixed 
with an equal quantity of fait of tartar; and being treated 
as in the firft experiment, produced one dram and eleven 
grains of neutral fait, con lifting of fat cubical cryftals ol 
regenerated fea-l'alt, intermixed with brown cryftals ot 
tartar of vitriol, which laft appeared to be in lefs propor- 
tion than in the former experiments. The filver, alter 
this operation, had the fame fpongy, filvery appearance 
as in the former experiments. The undiflblved part ol 
of the horn Iilver, which remained after its horn filver 
was extracted by the fpirit of hart’s-horn, retained its 
black colour. It was calcined in a crucible, and, during 
the calcination, a fulphureous fmell was obferved; the 
calcination was continued until this fmell ceafed. It had 
now an afh-colour, filvery appearance, and, during the 
operation, ftightly caked together, which made me think 
it had yet fome horn filver; I therefore digefted it with 
more fpirit of harts -horn ; and, having evaporated the 
folution flowly to drynels, I obtained thirty-four grains 
of horn filver; the undiflblved part here remaining, 
being melted with black flux, produced two drams and a 
half of pure filver, fo that black horn Iilver is compofcd 
of horn filver and fulpliurated Iilver. The lbhition of 
the 
