great care must be had lest the Spi∣rits
exhale. Which they will do, with∣out
the Glass have a strong guard; for
first, they are subtle; nor that only, but
ascend with a great impetus, by reason
of our Fire, which must cause the inferio∣ra
ebullire & moveri continuò, & infe∣riora
circulari, quolibet momento; and
thirdly, in Putrefaction the Body and
Spirits have a most subtle odour, which
also must be retained.
For preventing of all, thou shalt have
thy Stopple as firm as any part of thy
Glass, which let it be strong, as is said,
and the neck long and strong, and let
the neck be melted up with a Lamp, or
with Coals, and closed well without much
wringing, which makes the Glass brit∣tle;
but being nipt up, and after that
staying in the same heat, turning it to
and fro in the clear heat, the Glass will
come to as exactly close and smooth a su∣perficies,
as in any other place.
This is the true and sure way which
Philosophers have secured their Glasses
by. Let it cool by degrees, and be very
wary that it get no crack in cooling,