C H E M I 
and hydrogen gas is to be repeatedly introduced and 
fucked out. At laft it is to be filled with meafured 
quantities of this gas to the lip, which is to be comprefl'ed 
by a column of about four inches of water. 
The apparatus is now ready. The ball k of the elec¬ 
trical conductor, charged by a good machine, is to be 
brought near to the ball i; and while the Iparks pals in 
quick fucceffion from the wire Ae to the pointy of the 
tube Be, the cock at f is to be opened quickly, fo that- 
the firfl portion of hydrogen gas ifluing at e may be in- 
ftantly inflamed; the wire is then to be turned away 
from the flame. The combullion may be accelerated by 
increafing the column of water which prefles the hydro¬ 
gen gas, and leflening the preflure on the oxygen gas. 
The\dopter is now to be kept cool by water, allowed to 
trickle down over it from the veflel Ch During the com- 
buftion, meafured quantities of the gafes are to be intro¬ 
duced into the proper funnels; and, when it is wilhed to 
interrupt the procefs, the cock which admits the hydro¬ 
gen gals is to be quickly flopped. As the veffels cool, 
the oxygen gas and aqueous vapour in the adopter will 
contrail in bulk, and the water in the oxygen funnel 
will rile towards the brafs cap f. At this moment the 
cock muftbelhut, to prevent the water from rifmg higher. 
When the procefs is to be renewed, the oxygen funnel' 
is to be charged with gas, and the cock to be opened. 
The hydrogen funnel is next to be charged; the wore 
A e to be -turned to its' AkA pofition, and the eledli ic 
fpark to be applied as before. Thus the combullion may 
be carried on from day to day. That the eleflric fparks 
may llrike quickly, and vigoroufly, a communication 
fhould be made with U wire'between the culhion of the 
machine and the brafs capm. 
As the gafes employed are not to be conlidered as 
wholly free from azotic gas, its prefence will at lalt re¬ 
duce the gas in the adopter to the ftandara of atmo- 
fpheric air. The flame will then become weaker, and 
muft be watched, that the cock of the hydrogen funnel 
may be flopped before the flame is extinguilhed; other- 
wife fome of the hydrogen gas will pals unaltered into 
the adopter, and be confounded with the azotic gas, 
from which it is not ealily feparable. 
When the procefs is terminated, the quantity of hy¬ 
drogen gas remaining in its funnel, is to be noted from 
the gradations marked on the veflel, and to be dedudled 
from the fum of the meafures of the hydrogen gas em¬ 
ployed. This funnel is then to be fcrewed off. The 
oxygen funnel is to be treated in the fame manner, proper 
attention being paid to the level of the water, and to 
the temperature and preflure of the air at the time. The 
adopter and hoppers, being now in the ftate in which 
they were firfl weighed, are now to be weighed again, 
with the contained water, to determine its prelent weight. 
To weigh the water thus formed more accurately, and 
to examine its quality, it muft be drawn off from the 
adopter. For this purpole the adopter, after it has flood 
to drain for twenty-four hours, is to be warmed by wrap¬ 
ping the upper part of it in a hot doth : a bottle of a 
proper fize is to receive the^xtremity of the tube CD, 
and, the flop cock being opened, the expanded gas in 
the adopter will prefs all the water into the bottle. Du¬ 
ring the palfage of the water, the bottle is to be held at 
fuch a height that the orifice of the Hop cock may dip 
only one-eighth of an inch in the water; and when a 
fingle bubble of gas from the adopter has ilfued through 
the water, the flop cock is to be inflantly doled. 
The gas remaining in the adopter is now to be tranf- 
ferred into another veflel, in which it may be expofed 
firfl to lime-w'ater, that any carbonic acid gas contained 
in it may be meafured; and afterwards to fulphure of 
lime, which will imbibe all the oxygen gas, and leave 
the azotic gas in a ftate fit for menluration. The quan¬ 
tity of heterogeneous matter introduced with the gafes 
duping the combuftion, being thus difeovered, a pro¬ 
portionate deuuilion is to be made from the calculated 
S T R Y. 383 
weight of the hydrogen and oxygen gas employed. The 
difference of weight of the azotic gas remaining, and 
the common air at firfl weighed with the inftrument, 
may thus be ealily determined. 
The Society, from whole minutes this extraft was 
made, carried on the combuftion in the manner above 
deferibed, for about two hours at a time on different 
days, till the column of water in the tube CD was eight 
inches and a half in length. At each of thefe times the 
temperature of the gafes and the height of the barome¬ 
ter were carefully noted. In the manner deferibed by 
Lavoifier, the volume of each gas at 2985 inches of the 
barometer, and 54.'50 of thethermometer, was afeertained j 
and the weight of the oxygen gas confirmed was found to 
be 4i6 - 5grains, and that of the hydrogen gas 72-5 grains ; 
the weight of both being 489 gr. — 1 oz. n dvvt. 9 gr. 
The water produced weighed 1 oz. n dwt. 7 gr. ; and, 
contrary to all expectation, had nofenfible acidity. 
M. Des VIGNES’s APPARATUS, for preparing 
AERATED, ACIDULATED, op. MINERAL WA¬ 
TERS. 
Although we have, in page 210 of this volume, given, 
a defeription of Dr. Nooth’s apparatus for this purpofe ; 
and alfo of the improved one conftruCled by M. La 
Grange, both of which are delineated in the Chemiftry 
Plate III. yet the acknowledged utility of thefe waters, 
and an ardent defire of Amplifying the means of obtain¬ 
ing them, and of procuring, at pleafure, by artificial 
means, all the moft valuable mineral waters, will fuftici- 
entiy juflify our recurring to the fubjeft in this place. 
Water impregnated with carbonic acid gas, acquires 
the properties of Ample mineral waters, and poffefies all 
their medical qualities. The natural acidulous mineral 
waters do not differ from thefe except in holding other 
principles in folution ; and they maybe perfectly imitat¬ 
ed, when their analyfis is known. It is abfurd to think 
that art is incapable of imitating nature in the competi¬ 
tion of mineral waters. The operation is purely mecha¬ 
nical, confilling of the folution of certain known prin¬ 
ciples in water; w,e can and ought therefore to perform 
it dill better, as we have the power of varying the ma¬ 
terials, and proportioning the ftrength of any mineral 
water, to the purpofes for which-it is intended to be ap¬ 
plied. When properly made, the liquor fhouM have a 
brifk acidulous tafle, moft relembling Seltzer water. In 
an alkaline folution, if it be not perfedfly faturated with 
carbonic acid gas, it is apt, not only to be difagreeable 
to the tafle and ftomach, but alfo to prove irritating to 
the urinary paflages, which it rarely does when properly 
prepared. White powder of marble may be ufed for the 
production of carbonic acid gas, in preference to chalk. 
Des Vignes’s apparatus for preparing thefe waters, is 
delineated in the Chemillry Plate IX. fig. 2 ; and the fol¬ 
lowing is the defeription that chemift gives of it : A, the 
bottle or veflel in which marble, chalk, or any other proper 
fubftance, is to be put, with a little water. B a bottle 
containing fulphuric acid, and having its neck ground 
to fit in the firfl bottle at C, and a cock a, by which any 
quantity of the acid can be introduced to the chalk, or 
other fubftance. As the gas is extricated, it paffes through 
the tube D, into the veflel E, which contains the liquid 
to be faturated : the gas, by its elafticity, prefles the li¬ 
quor, and forces it through the tube F into G. At H, 
is a (mail hollow glafs ball I, with a item ground to fit 
the mouth of the veflel G, which it fhuts as a valve by 
the preflure of the liquor, aflifted with a fpiral fpring, 
until the water or other liquid, which has been forced 
through the tube F into G, prefles down by its weight 
the ball I, and returns back into E. When it accumu¬ 
lates to a certain point in E, the valve is again flint, and 
it riles through the tube F, as before. At b is a ftopper, 
to which hangs a finall weignt, about half an ounce, 
which a els as a fafety valve to prevent the preflure from 
reaching that point which would endanger the burfting 
of 
