WATERS, MINERAL. 
required in the experiments that are subser- 
vient to the ordinary purposes of life ; a ge- 
neral knowledge of the romposition of bo- 
dies being sufficient to assist in directing 
the most useful applications of them. In- 
stead therefore of giving a very ample de- 
tail of all the methods pointed out by Kir- 
wan and others, we shall describe the means 
wliich are most generally useful in re« 
searches of this kind. 
Before any proceeding is made in the 
analysis of a water, it is proper to inquire 
into its natural history, and to examine at- 
tentively its physical characters. The tem- 
perature of the water must be carefully ob- 
served, and the qtiantity inquired into, which 
it yields in a given time. The sensible qua- 
lities of taste, smell, degree of transparen- 
cy, &c. are also 'best ascertained at the 
fountaiu-iiead. The specific gravity of the 
water must also be found. See Gravity, 
specific- 
The readiest way of judging of the con- 
tents of mineial wafers are by applying 
tests or re-agents, the chief of which are the 
following : 
Infusion of litmus is a test of most un- 
combined acids. 
If the infusion redden the unboiled, but 
not the boiled water, we may infer, tliat 
the acid is volatile, and most probably, the 
carbonic. Sulphuretted hydrogen gas, dis- 
solved iu water, also reddens litmus, but 
not after boiling. 
To ascertain whether the change be pro- 
duced by carbonic acid, or by sulphuretted 
hydrogen, when experiiueiit shows that the 
reddening cause is volatile, add barytic wa- 
ter. This, if carbonic acid be present, will 
occasion a preihpitate, which will dissolve, 
•w'ith effervescence, on adding a little muri- 
atic acid. Sulpliuretted hydrogen may also 
be contained, along witli carbonic acid, in 
the same water; which will be determined 
by tlie tests hereafter to be described. Pa- 
per tinged with litmus is also reddened l)y 
tlie presence of carbonic acid, but regains 
its blue colour on drying. 
Infusion of Litmus reddened by Phosphoric 
Add,-— Tincture of Brazil wood, — Tincture 
of 'Turmeric, and Paper stained with each of 
these three Substances, — Tincture of Red Cab- 
bage.— All these different tests have one 
and the same object. 
Infusion of litmus, reddened by phospho- 
ric acid, or litmus paper reddened by it, 
has its blue colour restored by alkalies and 
earths, and by carbonated alkalies and car- 
bonated earths. Turmeric paper and tinc- 
ture are changed to a reddish brown by 
alkalies, whether freed fiom carbonic acid 
or not; by earths, freed from carbonic acid, 
but not by carbonated eartlis. 
The red infusion of Brazil-wood, and pa- 
per stained with it, become' blue by alka- 
lies and earths, and even by the latter, 
W'hcn dissolved by an excess of carbonic 
acid. In the last mentioned case, however, 
tire change will either cease to appear, or 
will be much less remarkable when the wa- 
ter lias been boiled. 
Tincture of' cabbage is, by the same 
causes, tniiied green ; as is also paper stain- 
ed with the juice of the violet, or with the 
scrapings of radishes. 
Tincture of gulls, — Tincture of galls is 
employed for discovering iron, with which 
it produces a black tinge. The iron, how- 
ever, in order to be detected by this test, 
must be in the state of a red oxide, or, if 
oxydized in a less degree, its effects will not 
be apparent, unless after standing some 
time in contact with the air. By applying 
this test before and after evaporation, or 
boiling, we may know whether the iron be 
held in solution by carbonic acid, or by a 
fixed acid ; for, 
1. If it produce its effect before the ap- 
plication of heat, and not afterward, carbo- 
nic acid is the solvent. 
2. If after, as well as before, a fixed and 
vulgarly called mineral acid is the solvent. 
3. If, by the boiling, a yellowish pow- 
der be precipitated, and yet galls continue 
to strike the water black, the iron, as often 
happens, is dissolved both by carbonic 
acid gas and by a fixed acid. 
Sulphuric Acid. — Sulphuric acid discovers, 
by a slight effervescence, the presence of 
carlionic acid, whether uncombiued or unit- 
ed with alkalies or earths. 
2. If lime be present, the addition of sul- 
phuric acid occasions, after a few days, a 
white precipitate. 
3. Barytes is piecipatcd instantly, in the 
form of a white powder. 
4. Nitric or muriatic salts, in a dry state, 
or dissolved in very little water, on adding 
sulphuric acid, and applying heat, are de- 
composed : and if a stopper, moistenetl with 
solution of ammonia, be held over the ves- 
sel, white clouds will appear. For distin- 
guishing whether nitric or muriatic acid be 
the cause of this appearance, rules will be 
given hereafter. 
Oxalic Add and Oxalates. — This acid is 
a most delicate test of lime, which it sepa- 
rates from ail its combinations. 
