154 Apparatus for producing Water, Be. . 
_ To weigh, the water thus formed fiill more accurately, and, 
to examine its quality, it muft be drawn off from the adopter. 
For this purpofe the adopter, after it has ftood to drain for 24 
hours, is to be warmed by wrapping the upper part of it in 
a hot cloth: a bottle of proper fize is to receive the extremity, 
of the tube € D, and, the ftop cock bemg opened, the ex- 
panded gas in the adopter will prefs all the water intothe 
bottle. During the paffage of the water, the bottle is to be 
held at fuch a height that the orifice of the {top cock may dip, 
only 3th of an inch in the water; and when a fingle bubble 
ef gas from the adopter has. iffued through the water, the 
fiop cock is to be inftantly clofed. 
The gas remaining in the adopter is now to be transferred: 
ato another veflel, in which it may be expofed firft to lime 
water, that any carbonic acid gas contained im it may be 
meafured ; and afterwards fo fulphuret of lime, which will, 
ymbibe all the oxygen gas, and leave the azotic gas in a ftate 
fit for menfuration. 
The quantity of heterogeneous matter introduced with 
the gafes during the combutftion being thus difcovered, a pro-- 
portionate deduction is to be made from the calculated weight 
of the hydrogen and oxygen gas employed. The difference of 
weight of the azotic gas remaining, and the common air at firft 
weighed with the inftrament, may thus be eafily determined, 
The Society from whofe interefting minutes we make the 
prefent extract, carried on the combuftion in the manner al- 
ready defcribed, for about two hours at a time on different 
days, til] the column of water in the tube C D was 8+ inches 
in length. Ateach of thefe times the temperature of the 
gafes and the height of the barometer were carefully noted. 
In the manner defcribed by Lavoifier, the volume of each 
gas at 29°85 inches of the barometer, and 54°5° of the ther-~ 
mometer, was afcertained ; and the weight of the oxygen gas 
confumed was found to be 436'5 grains, and that of the hy- 
drogen gas 725 grains; the weight of both being 489 gr. 
= 1 0%. 11 dwt. Q gr. 
