fome Thermometric al 'Experiments. 5 \ g 
lug the bottle very often, or by long keeping, the cork becomes 
loofe, in which cafe it muft be changed ; and thus ether, fpirit 
of wine, or any fluid, excepting thofe which corrode cork, 
may be preferved. 
I fhall now defcribe a method of purifying vitriolic ether, 
which is very eafy and expeditious, though not very profitable : 
this method I learned of Mr. winch, Chemift, in the Hay- 
market. Fill about a quarter of a ftrong bottle with common 
ether, and upon it pour . about twice as much water, then flop 
the bottle, and give it a fhake, fo as to mix for a time the ether 
with the water. This done, keep the bottle without motion, 
and with the mouth downwards, till the ether is ieparated from 
the water andfwims over it, which requires not above three or 
four minutes of time ; then open the bottle, and keeping it flill 
inverted, let the greateft part of the water come out very 
gently ; after this the bottle being turned with the mouth up- 
wards, more water muft; be poured in it, and in fhort the 
fame operation muft be repeated three or four times. Laftly, 
all the water being feparated from the ether by decanting it 
with dexterity, the ether will be found to be exceedingly pure* 
By this means I have purified common vitriolic ether, which 
could not afFedl elaftic gum, and have reduced it into fuch a 
ftate as that elaftic gum was eafily difiblved by it. Indeed this 
purified ether appeared by every trial to be purer than I ever 
faw it, even when made after the beft ufual method, and in 
the moft careful manner. The only inconvenience attending 
this procefs is, that a vaft quantity of ether is loft. Not 
above three or four ounces of a pound of common ether 
remain after the purification. As the greateft part of the ether 
Is certainly mixed with the water that is ufed in the procefs, it 
may perhaps be worth while to put that water into a retort, and 
Vol, LXX'L Y y y to 
