1824.] - 
there were three or four atmospheres ; 
the tube remained perfectly clear «nd 
dry, bat on-evoling one end. to“ 0°, the 
fluid suiphurovs acid condensed, and in 
all its characters Was Tike that prepared 
by the furmer process, " 
A stall gage was attached {o a‘tabe 
in which salphurous acid was afterwards 
forme , and at a fempeérature of 45° F. 
tie sure within, the tube, was equal 
io three atmospheres, there being, a 
portion, ef Jignid. sulphurous: acid. pre- 
sent: but, as the.eommon air had. not 
been: excluded’ when the tube was 
sealed; nearly one atmosphere must be 
dué 10 its presence, so that sulphurous 
acid ‘Vapour exerts a’ pressure of about 
two atmospheres at 45° F. Its specific 
gravity was nearly 1.42. 
Sulphuretted Hydrogen.—Atube being 
bent, and sealed at the shorter end, 
strong muriatic acid Was poured in 
through a small funnel, so as nearly to 
fill the short leg without soiling the long 
one... A.piece of platinum foil was then 
crumbled.up and pushed in, and upon 
that were put fragments of sulphuret of 
iron, until the tube was nearly full. In 
this way action was prevented until the 
tube was sealed. If it once commences, 
it is almest impossible ‘to close the tube 
in a manner sufficiently strong, because 
of the pressing out of the gas, When 
closed, the muriatic acid was made to 
ron on to the sulphuret of iron, and then 
left for a day or two. At the end of 
that tine, much, proto-muriate of iron 
had formed; aud, on placing the clean 
end.of.the tube in a mixture of ice and 
a nis urming the other end if necessary 
by, a ie water, sulpburetted hydrogen 
Mii iguid state distilled over, 
The liquid sulphuretted hydrogen was 
lourless, limpid, and excessively fluid. 
ra er, when compared with it in similar 
tnies, appeared tenacious and oily. It 
did not mix with the rest of the fluid in 
the tube, which was no doubt satu- 
sah d, but remained standing on. it, 
W aes a tube containing it was opened, 
the liquor immediately rushed into 
vapour;, and this being done under 
wi ter, and the vapour collected and ex- 
amined, it proved to be sulphnretted 
hydrogen, gas. As.the temperature of 
a containing some of it rose from 
OH ted ©, part of the fluid rose in va- 
pour, and its bulk, diminished; but 
there was no, other change: it did not 
seem more adhesive at 0° than at 45°. 
Its tekaclive power appeared to be 
rather greater than that of water; it 
» decidedly surpassed that of sulphurous 
3 
Proceedings of Public Societies. 
533 
acid. A small gage being introduced 
into. a tube in which liquid salphuretted 
hydrogen was afterwards prodneed, it 
was found. that,.the. pressure: of its 
vapour, was nearly equal, to. seventeen 
atmospheres at the temperature of 50°, 
The gages used were, made, by draw; 
ing out some. tubes -at. the blow-pipe 
table until they, were capillary, and of a 
trumpet form; they were graduated by 
bringing a small portion of mercury suc, 
cessively into their diferent parts ;, they 
were then sealed at the fine end, and a 
portion of mercury placed in the broad 
end; and in this state they were placed 
in the tubes, so. that none of the sub- 
stances used, or produced, could get to 
the mercury, or pass by it to the. inside 
of the gage. In estimating the number 
of atmospheres, one has, always. been 
subtracted for the air left in the tube. 
The specific gravity of sulphuretted 
hydrogen appeared to be 0.9. 
Carbonic Acid—The materials, used 
in the production of carbonic acid, were 
carbonate of ammonia and concentrated 
sulphuric acid; the manipulation was 
like that deseribed for sulphuretted hy- 
drogen. Much stronger tubes are how- 
ever required for carbonic acid than for 
any of tbe former substances, and there 
is none which has produced so many or 
more powerful explosions. ‘Tubes which 
have held fluid carbonic acid well for 
two or three weeks together, have, upon 
some increase in the warmth of ‘the 
weather, spontaneously exploded with 
great violence; and the precautions of 
glass masks, goggles, &¢c. which are. at 
all times necessary in. pursuing these 
experiments, are particularly so with 
carbonic acid. 
Carbonic acid is a Jimpid colourless 
body, extremely fluid, and floating apon_ 
the other contents of the tube.) It dis- 
tils readily, and rapidly at the difference 
of temperature between 32°) and:.0°, 
Its refractive power_is much less than 
that of water. No diminution of tem- 
perature to which Ihave been able to 
submit, it, has, altered.its: appearance. 
Tn endeavouring to open the tubes at 
one end, they have uniformly. burst into 
fragments, with | powerful explosions. 
By inclosing a gage ina tube.in which 
fluid ¢arbonic acid was afterwards pro- 
duced, it was found) that) ils: vapour 
exerted a pressure of 36. atmospheres at 
a temperature of 82°. 
It may be, questioned, perhaps, whe- 
ther this and other similar fluids: ob- 
tained from, materials containing water, 
do not contain a portion of that fluid ; 
in 
