Potash potash.
Soda soda.
Ammoniac ammoniac.
Oxyd of
zinc zinc.
iron iron.
lead lead.
tin tin.
cobalt cobalt.
copper copper.
nickel nickel.
mercury mercury.
Argill argill.
_Note._--Most of these combinations were neither known nor named by the
old chemists. The boracic acid was formerly called _sedative salt_, and
its compounds _borax_, with base of fixed vegetable alkali, &c.--A.
SECT. XXII.--_Observations upon Boracic Add and its Combinations._
This is a concrete acid, extracted from a salt procured from India
called _borax_ or _tincall_. Although borax has been very long employed
in the arts, we have as yet very imperfect knowledge of its origin, and
of the methods by which it is extracted and purified; there is reason to
believe it to be a native salt, found in the earth in certain parts of
the east, and in the water of some lakes. The whole trade of borax is in
the hands of the Dutch, who have been exclusively possessed of the art
of purifying it till very lately, that Messrs L'Eguillier of Paris have
rivalled them in the manufacture; but the process still remains a secret
to the world.
By chemical analysis we learn that borax is a neutral salt with excess
of base, consisting of soda, partly saturated with a peculiar acid long
called _Homberg's sedative salt_, now _the boracic acid_. This acid is
found in an uncombined state in the waters of certain lakes. That of
Cherchiais in Italy contains 94-1/2 grains in each pint of water.
To obtain boracic acid, dissolve some borax in boiling water, filtrate
the solution, and add sulphuric acid, or any other having greater
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