1824.) . 
ammonia, it became necessary, though 
difficult, to find.some dry source of that 
substance; and J, at last, resorted, to\ a 
compound *of it, whichy E, had occasion 
to nutice some years since with chloride 
of silyer., y/When dry. chloride of psilver 
is pnt, imte,ammoniacal gas, as dry, as 
it canbe made, it absorbs a large quan- 
tity, of jit; 100.grains condensing above 
130, eubieal;inches.of the gas: but the 
compound, thus’ formed, is decomposed 
by a temperatare of 100° FP. or upwards, 
A portion,of, this compound was sealed 
up in.a bent tube, and heated in one 
leg, whilst the other was cooled by ice 
or. water. The compound thus heated 
under. pressure fused at.a comparatively 
low temperature, and boiled up, giving 
off ammoniacal gas, which condensed 
at the opposite end into a liquid. 
Liquid ammonia, thus obtained was 
colourless, transparent, and very fluid. 
Its, refractive power surpassed that of 
any. other, of the fluids described, and 
that also of water itself, From the way 
in which°it. was obtained, it. was, evi- 
dently, as,free from water as ammonia 
in, any state could. be. When the 
chloride of silver is allowed to cool, the, 
ammonia immediately returns to if, 
combining with it, and producing the 
original compound. During this action 
a, curious combination of effects takes 
place: as the chloride absorbs the am- 
monia, heatiis produced, the tempera- 
tare rising. up nearly to 100°; whilst a 
few) inches, off, at. the opposite end of 
the tube,: considerable cold is produced 
by ithe evaporation of the fluid. When 
the, whole is'retained at the temperature 
of 60°, the, ammonia boils till it is dis- 
sipated and_re-combined, The pressure 
of the vapour of ammonia is equal to 
ahont 6.5,atmospheres at 50°, Its spe- 
cific gravity was 0.76. 
Muriatie Acid,— When made from 
pure muriate of ammonia and sulphuric 
acid, liquid muriatic acid is obtained 
colourless, as Sir Humphry Dayy had 
anticipated. “Ets refractive power is 
seatet than that of nitrous oxide, but 
iss, than. that of water; it is nearly 
equal to that of carbonic acid, The 
pressure of its vapour at the temperature 
of 50°, is equal to about 40 atmos- 
FOB. 1 
Chlorine.—The_ refractive power of 
fluid, chlorine is rather less than that of 
water. The pressure of its, vapour, at 
60° is, nearly equal to 4 atmospheres, |, 
.® Quarterly Journal/of Science, vol. v. 
p74. 
Proceedings of Public Societies. 
535 
Attempts have been made fo obtain 
hydrogen, oxygen, fluoboracic, fluosi- 
licic, and phosphuretted hydrogen; gases 
in-the liquid state; bat, though’ allof 
them have been subjected torgreat-pres-. 
sure, they have as yet resisted conden-. 
sation. The difficulty with: regard) to 
fluoboric gas consists, probably, in: its 
aflinity for sulphuric acid, which; as Dr. 
Davy has shown, is so great as to raise 
the sulphuric acid with it)in vapour. 
The experiments will, however, be con- 
tinued. on these and other gases, in the 
hopes that some of them, atileast, will 
ultimately condense. 
On. the Application of Liquids formed by 
the condensation of Gases as mecha- 
nical agents ; by Sir HuMPHRY Davy, 
Bart. Pres. RS: - igh 
One. of the principal objects that I 
had in view, in causing experiments to 
be made on the condensation of different 
gaseous: bodies, by generating . them 
under pressure, was the hope of obtain- 
ing vapours, which, from the: -facility 
with which their elastic forces might be 
diminished» or increased, by small de- 
crements or increments of temperature, 
would be applicable to the same pur- 
poses as steam. itd 
-As soon as I had obtained muriatic . 
acid in the liquid state, a body which 
M. Bertholet supposed owed its power 
of being separated front bases by other 
acids, only to the facility with which it 
assumes the gaseous form, I bad no 
doubt, as I mentioned in my last com- 
munication, that all the other \gases 
which have weaker affinities or greater 
densities, and which are ‘absorbable to 
any extent by water, might be rendered 
fluid by similar means; and, tliat: the 
conjecture was founded, has been:proxett 
by the experiments made with'so much 
industry and ingenuity by Mr. Faraday, 
and which: Ihave had the pleasure of 
communicating to the society.) 90!) 
The elasticity: of vapours.jin: contact 
with the Jiquids from which they are 
produced, under bigh pressures, by high 
temperatures, such as thase of alcoliol 
and water, is :knowe. tovinerease in a 
much higher ratio than the arithmetical 
one of the temperature ;. but the exact 
law is not yet determined; and the re- 
sult is a complicated one, and: depends 
upon circumstances which require to be 
ascertained by experiment. Thus the 
ratio of the elastic force, dependent 
upon pressure, is to be combined with 
that of the.expansive force dependent 
upon temperature ; and the: greater loss 
of radiant heat at high base Ad 
: an 
