3S4 C H E M 
of the veffels. The advantage which this apparatus pof- 
feffes, is, that it not only gives the fame preffure of the 
gas upon the fill-face of the liquor to be impregnated, 
which the common machines do, but, by the conffant 
agitation which is kept up, by the afcent and defcent of 
the fluid, continually expofes a freflr l'urface of it to its 
a&ion : by which means water or other liquors may be 
as fully faturated in two hours as they can in twelve by 
any apparatus in common ufe. 
Fig. 3, is a feftion of the valve ball I, the fpiral fpring 
K, and the cork L, to which the two former are faffened. 
At c is a piece of lead, which ferves at the fame time to 
adjuft the weight of the ball, and to keep it in an up¬ 
right pofition. 
Fig. 4, is a plan of the cork, {hewing the apertures 
through which the liquor delcends. The tubes D and F 
are each in two parts, joined by pieces of elaltic gum, 
by which means the apparatus admits of being moved 
without danger of breaking. There is alfo a glafs rod e 
in the veflel A for the purpofe of ftirring the materials. 
This rod paffes tight through a piece of elaftic gum (the 
mouth end of one of the common bottles made of that 
fubltar.ee), the ether end of which is fitted clofe to the 
mouth of the veflel A, by means of wire or catgut wound 
round it, to prevent the el'cape of the gas. 
Dr. Fierlinger has propofed the following very Ample 
method for impregnating water with carbonic acid gas. 
He fills common round bottles with water, inverts them 
carefully under water, in order to prevent any air from 
entering, and charges them in the ufual method with 
carbonic acid gas. He then corks the bottles, thus filled, 
under the water, with a ventilated ftopper, immerfes them 
under water in a proper cylindrical, almoff tubular ffiap- 
ed, veflel, two feet high, and of a^ proportionate width 
to the diameter of the bottle, in order to apply, by means 
of hydroftatic laws, a great preffure with a fmall quan¬ 
tity of water. The bottles thus filled with the gas, and 
entirely immerfed, imbibe water by means of the affinity 
the carbonic acid gas has for it, in fuch a manner that 
they are nearly filled; and water is thereby obtained, 
impregnated with an equal volume of gas, the water 
having lodged itfelf in the interftices of the gas. It is 
pretty ftrong, and can be made Hill more fo. This me¬ 
thod has, befides its conveniency and cheapnefs, Hill 
other advantages ; the degree of impregnation may be 
regulated by the height of the column of water under 
which the bottle is immerfed, and the water is prepared 
in thofe veffels out of which it is to be drunk, and this pre¬ 
vents that efcape of gas which always takes place when 
poured from, one veflel to another, efpecially if the wa¬ 
ter be ftrongly impregnated. The above-mentioned ven¬ 
tilated Hoppers are only corks, fitted exadtly to the bot¬ 
tles, perforated lengthways, by holes drilled through 
them,- the uppermolt orifices of which are covered with 
a {'mail plate of pewter, {'aliened to the cork by means 
of a Hring paffed through a hole in the centre, and drawn 
through the cork. If this fmall plate be furnifhed with 
a little cavity, in which iron filings are put, the water 
becomes chalybeate. 
APPARATUS for FREEZING MERCURY. 
The freezing or fixing of mercury, has been the means 
of proving it to be a metal, poffefling the principal pro¬ 
perties and charadleriftics of other metals, as lplendour, 
malleability, and a cryfiallized flrudlure when reduced 
to a folid form. Gmelin was the firff who obferved mer¬ 
cury at fuch a low temperature as leads to a belief that 
a partial congelation had taken place, though he did not 
then fufpedl the fa£l 5 but De L’ifle was probably the firff 
perfon upon earth who law quickfilver reduced to a folid 
form by cold, and ventured to credit the teflimony of his 
fenfes. Th:s happened at Yakutlk in Siberia, in 1736, 
where the natural temperature was fo low as to produce 
the effedl without the aid of artificial means. 
Since that period, the production of artificial cold,-by 
: S T R Y. 
means of various mixtures, fufficiently intenfe to freeze 
mercury, has employed the abilities of the mod experi¬ 
enced chemifts and philofophers. The materials employed 
by Seguin, for frigorific mixtures, are however the belt 
that have yet been propofed, or perhaps can poffibly be 
deviled. Confidering the muriats as a clafs of falts beft 
fuited for the purpole, and having tried them all, he gave 
the decided preference to muriat of lime in cryffals. His 
method was to mix the cryffals, previoufly pulverifed., 
with an equal weight of uncompreffed fnow. Meffrs. 
Pepys, Allen, and Lawfon, feem to have been the firff, 
wdio in this country tried that method : this was in De¬ 
cember 1798; and they fucceeded perfeijlly in freezing 
the mercury. We {hall give the account of it as com¬ 
municated by Mr. Pepys himlelf, in the Philofophical 
Magazine. 
“ Determining to make the experiment with accuracy 
in refpedl to the weight of the materials employed, and 
on fuch a fcale that it might be repeated by any one, on 
the 30th of January 1799, we collected a quantity of fnow 
for the purpofe. The temperature of the laboratory at 
the fame time was 40 0 . It may not be improper to men¬ 
tion here, that the thermometer employed in this and 
the other experiments which followed, was filled with 
tinged, alcohol, and accurately divided according toFah- 
renheit’s fcale, as mercurial thermometers cannot be re- 
forted to for determining degrees of temperature at or 
under the freezing point of that metal. Having put into 
an earthen pan equal parts of muriat of lime of the tem¬ 
perature of 40 0 , and fnow at 32° above o°, we found- 
that the temperature of the mixture, as foon as lique¬ 
faction took place, was 32 0 below o°. Into this mixture 
we immerfed, each in feparate veffels, eight ounces troy 
of muriat of lime, and the fame weight of {'now, by which 
means, and with very little trouble, they were cooled 
down to 5 0 above o°, the mixture gaining a proportionate 
increafe of temperature by the heat which had paffed into 
it from the immerfed fnow and muriat. 
We now placed a half-pint Wedgewood’s cup within a 
white ftone-ware jar, infulating it with three corks placed 
at equal diffances round the veflel, and one at the bottom 
for the cup to reff upon. This prevented the cup from 
coming in contaCl with the jar, which we now placed, 
with the cup in it, in the mixture that had ferved for 
cooling the materials down to 5 0 above zero, adding to 
the mixture.a little more muriat of lime at 40 0 and {now 
at 32 0 . By this means we fecured the advantage of hav¬ 
ing a" cold atmofphere, within the jar, all round the in- 
fulated cup. 
Upon mixing the cooled ingredients, which were now- 
put into the cup, the thermometer, being immerfed in 
the mixture, funk to 50 0 below zero. Four ounces of 
pure mercury at 40 0 above o, in a fmall thin glals retort, 
were then introduced into the mixture, which in fifteen 
minutes became perfeftly fixed. We obferved that it 
congealed from the circumference towards the centre, in 
the fame way as wax or refin fixes in cooling. We now 
broke the retort, and gave the mercury leveral blows 
with the beak of a hammer, which indented, and at laft 
fraftured it: the frafture was fimilar to that of zink, but 
with facets more cubical. Inadvertently taking up a 
piece of the folid mercury, I experienced a fenlation as 
if I had received a wound from a rough-edged inffru- 
ment. I threw it from me as I would have done apiece of, 
red-hot iron, and was not a little alarmed when I found 
that the part of my hand which had been in contaft with 
the metal, immediately after loff all fenfation, and be¬ 
came white and dead to the view. 
The mercury in the mean time had become fluid. The 
time that had paffed from taking it out of the mixture 
might have been about two minutes ; but the accident 
that happened to my hand prevented me from noting it 
exaftly. On trying the temperature of the mixture, I 
now found it 42 0 below o ; the addition of fome {now, 
which had been cooled for the purpole while the preced¬ 
ing 
