A SYSTEM OF 
^14 
ford both in medicine and common life. The 
bilmuth, it is true, has likewife in its time been in 
fome favour with adepts *, but it foon loft its credit, 
and was left to thofe who contented themfelves 
with lefs profpeds than of making gold and the 
uriiverfai medicine ; as to pewterers, tin-workers, 
and other tradefmen, who find their advantage in 
the fufibillty of this femi-nietal, and its giving co- 
lour and hardnefs to tin and lead. 
SECT. CCXXVIL 
3. Zink, Speltrc, Zincum, 
a. Its colour comes neareft to that of lead, 
but it does not fo eafily tarnifti. 
bo It ftiews a texture, when it is, broken, as 
if it were compounded of flat pyramids. 
€0 Its fpecific gravity to water is, as 6,900 or 
7000 : : tooo. 
d> It melts in the fire before it has acquired 
a glowing heat ; but when it has gained 
that degree of heat, it burns with a flame 
of a changeable colour, between blue and 
yellow ; and \f in an open fire, the calx 
riles in form of foft white flov/ers i but if 
in a covered veftel, with the addition of 
ibme inflammable, it is diftiiled m a me- 
tallic form j in which operation, howeverj 
part of it is fometimes found vitrified, 
e. It unites with all the metals, except bif- 
inuth, and makes them volatile. It is 
however not eafy to unite it with iron with- 
out the addition of fulphur. It has thq 
ftrongeft attraction to gold and copper, 
and this lail metal acquires a yellow colour 
byi:^ which has occafioned many experk 
