1815.) the Gases by different Bodies. ‘S47 
perceiving that no more air collected in it. It was then completely 
filled, shut with a glass stopper under the boiling water, and placed 
inverted over mercury. 
2. I filled over the pneumatic water-trough a flask, M, capable 
of holding 250 cubic centimetres, with the gas to be absorbed, held 
it inverted for half an hour under the water of the trough, that it 
might acquire the same temperature with this liquid, which ought 
to be nearly that of the atmospherical air. I then shut its mouth 
under the surface of the water with a glass stopper. This stopper 
must be carefully wiped, that no air bubbles be left on it; and it 
ought to be conical, that it may not compress the gas when intro- 
duced. The weight of this flask empty and full of water was accu- 
rately determined. 
3. From this flask I poured over the mercurial trough about the 
sixth part of the gas into a receiver filled with mercury. | This por- 
tion of gas was then poured over the water trowgh into a flask, N, 
filled with water. This flask, being weighed before and after the 
introduction of the gas, gave the volume of this last. This volume 
being abstracted from that in the flask M originally, gave the quan- 
tity of gas still remaining in that flask. 
_ 4, I now opened under mercury an inverted flask full of well 
boiled water, and poured as much of this water through the mer- 
cury into the flask, M, as expelled all the mercury which had been 
introduced into it by the third operation, The flask, M, was now 
shut at the surface of the mercury, and weighed. ‘This gave the 
volume of water introduced: into the flask. ° 
5. The gas with the water was now strongly agitated for 15 
minutes, while the flask, M, was held by a pair of pincers, to prevent 
the introduction of any heat from the hand. It was then plunged 
under the water of the trough, to bring it exactly to its original 
temperature, opened in an inverted position, and shut again under 
water. Now the water which occupied the place of the absorbed 
gas, and the difference between the weight of the flask, M, now and 
when it was full of water, enabled me to know the volume of gas 
absorbed. 
ArTICLE III. 
An Analysis of the Mineral Waters of Dunblane and Pitcaithly 5 
with General Observations on the Analysis of Mineral. Waters, 
and the Composition of Bath Water, &c, By John Murray, 
M.D. F.R.S.E. 
(Continued from p. 269.) 
Iil.—-OBSERVATIONS ON THE COMPOSITION OF SALINE MINERAL 
WATERS. 
Ir isa mere not unequivocally determined, and perhaps not 
capable of being determined, in what state the saline ingredients of 
