WATERS, 
mixture be kept twenty-four hours. Then 
■withdraw the stopper under water, a quan- 
tity of which fluid will immediately rush in. 
Allow the bottle to stand half an hour with 
out agitation. The redundant oxymuriatic 
acid gas will thus be absorbed ; and very 
little of the carbonic acid will disappear. 
Su])posing that, to ten cubic inches of the 
mixed gases, ten incites of oxymuriatic gas 
have been added, and that, after absorp- 
tion, by standing over water, five inches re- 
main, the result of this experiment shows, 
that the mixture consisted of equal parts of 
sulphuretted hydrogen and carbonic acid 
gases. 
Whenever this complicated admixture of 
gases occurs, as in the Harrowgate, and in 
some of the Cheltenham waters, it is ad- 
visable to operate separately on two por- 
tions of gas, with the view to determine, by 
the one, the quantity of carbonic acid and 
sulphuretted hydrogen ; and that of azote 
and oxygen by the other. In the latter in- 
stance, remove both the absorbable gases 
by caustic potash, and examine the remain- 
der in the manner already directed. 
Nitrogen gas sometimes occurs in mine- 
ral waters, almost in an unmixed state. 
Wlien this happens, the gas will be known 
by the characters already described as be- 
longing to it. Sulphureous acid gas may 
be detected by its peculiar smell of burning 
sulphur, and by its discharging fhe colour-' 
of an infusion of roses, which has been red- 
dened by the smallest quantity of any acid 
adequate to the effect. 
(«) The water should next be evaporated 
to dryness. The dry mass, when collected 
and accurately weighed, is to be put in a 
bottle, and highly rectified alcohol poured 
on it, to the depth of an inch. After hav- 
ing stood a few hours, and been occasion- 
ally shaken, pour the whole on a filter, wash 
it with a little more alcohol, and dry and 
weigh the ren)ainder. 
(h) To the undissolved residue add nine 
times its weight 'of cold distilled water; 
shake the mixture frequently; and, after 
some time, filter ; ascertaining the loss of 
weight. 
(c) Boil the residuum, for a quarter of 
an hour, in sometimes more than five hun- 
dred times its weight of water, and after- 
wards filter. 
(d) The residue, which must be dried 
and weighed, is no longer soluble in water 
or alcohol. If it has a brown colour, de- 
noting the presence of iron, let it be moist- 
MINERAL. 
ened with water, and exposed to the sun'# 
rays for some weeks. 
I. The sohition in alcohol (a) may con- 
tain one or all of the following salts : mu- 
riates of lime, magnesia, or barytes, or ni- 
trates of the same earths. Sometimes, also, 
the alcohol may take up sulphate of iron, ;n 
which the metal i^ highly oxydized, as will 
appear by its reddish-brown colour. 
1. In order to discover the quality and 
quantity of the ingredients, evaporate to 
dryness; weigh the residuum; add above 
half its weight of strong sulphuric acid ; and 
apply a moderate heat. The muriatic or 
nitric acid will be expelled, and will be 
know'n by the colour of their fumes ; the 
former being white, and the latter orange- 
coloured. 
2. To ascertain whether lime or magne- 
sia be the basis of the salts, let'the beat be 
continued till no more fumes arise, and let 
it then be raised to expel the excess of sul- 
phuric acid. To the dry mass, add twice 
its weight of distilled water. This will take 
up the sulphate of magnesia, and leave the 
sulphate ot lime. The two sulphates may 
be separately decomposed, by boiling with 
three or four times their weight of carbo- 
nate of potash. The carbonates of lime 
and magnesia, thus obtained, may be sepa- 
rately dissolved in muriatic acid, and eva- 
porated. Tlie weight of the dry salts will 
inform «s bow much of each the alcohol bad 
taken up. Lime and magnesia may also be 
separated by the use of phosphate of soda. 
II. The watery solution (b) may contain 
a variety of salts, the accurate separation 
of whicli from each other is a problem of 
considerable difficulty. 
1. The analysis of this solution may be 
attempted by crystallization. For this pur- 
pose let one half be evaporated by a very 
gentle beat, not exceeding 80“ or 90“. 
Should any crystals appear on the surface 
of the solution, while hot, in the form of a 
pellicle, let them be separated and dried 
on bibulous paper. These are muriate of 
soda, or common salt. The remaining so- 
lution, on cooling very gradually, will per- 
haps affoid crystals distinguislrable by their 
form and other qualifies. When various 
salts, however, are contained in tbq same 
solution, it is extremely difficult to obtain 
them sufficiently distinct to ascertain their 
kind. 
2. The nature of the saline contents must 
therefore be examined by tests, or re- 
agents. 
