19

Of the Composition and general Properties of the Alkalies. --Of
Potash. --Manner of preparing it. --Pearlash. --Soap. --Carbonat of
Potash. --Chemical Nomenclature. --Solution of Potash. --Of Glass.
--Of Nitrat of Potash or Saltpetre. --Effect of Alkalies on
Vegetable Colours. --Of Soda. --Of Ammonia or Volatile Alkali.
--Muriat of Ammonia. --Ammoniacal Gas. --Composition of Ammonia.
--Hartshorn and Sal Volatile. --Combustion of Ammoniacal Gas.

CONVERSATION XV.

ON EARTHS. 44

Composition of the Earths. --Of their Incombustibility. --Form the
Basis of all Minerals. --Their Alkaline Properties. --Silex; its
Properties and Uses in the Arts. --Alumine; its Uses in Pottery, &c.
--Alkaline Earths. --Barytes. --Lime; its extensive chemical
Properties and Uses in the Arts. --Magnesia. --Strontian.

CONVERSATION XVI.

ON ACIDS. 69

Nomenclature of the Acids. --Of the Classification of Acids. --1st
Class --Acids of simple and known Radicals, or Mineral Acids.
--2d Class --Acids of double Radicals, or Vegetable Acids.
--3d Class --Acids of triple Radicals or Animal Acids. --Of the
Decomposition of Acids of the 1st Class by Combustible bodies.

CONVERSATION XVII.

OF THE SULPHURIC AND PHOSPHORIC ACIDS: OR, THE COMBINATIONS OF
OXYGEN WITH SULPHUR AND WITH PHOSPHORUS; AND OF THE SULPHATS
AND PHOSPHATS. 80

Of the Sulphuric Acid. --Combustion of Animal or Vegetable Bodies by
this Acid. --Method of preparing it. -- The Sulphurous Acid obtained
in the Form of Gas. --May be obtained from Sulphuric Acid. --May be
reduced to Sulphur. --Is absorbable by Water. --Destroys Vegetable
Colours. --Oxyd of Sulphur. --Of Salts in general. --Sulphats.
--Sulphat of Potash, or Sal Polychrest. --Cold produced by the
melting of Salts. --Sulphat of Soda, or Glauber's Salt. --Heat
evolved during the Formation of Salts. --Crystallisation of Salts.
--Water of Crystallisation. --Efflorescence and Deliquescence of
Salts. --Sulphat of Lime, Gypsum or Plaister of Paris. --Sulphat of
Magnesia. --Sulphat of Alumine, or Alum. --Sulphat of Iron. --Of
Ink. --Of the Phosphoric and Phosphorous Acids. --Phosphorus
obtained from Bones. --Phosphat of Lime.

CONVERSATION XVIII.

OF THE NITRIC AND CARBONIC ACIDS: OR THE COMBINATION OF
OXYGEN WITH NITROGEN