the accuracy of his processes and the correctness of his
conclusions. Thus he formed, for instance, pumice-stone, feldspar,
mica, iron pyrites, &c. artificially.

But of all the achievements of inorganic chemistry, the artificial
formation of lapis lazuli was the most brilliant and the most
conclusive. This mineral, as presented to us by nature, is
calculated powerfully to arrest our attention by its beautiful
azure-blue colour, its remaining unchanged by exposure to air or to
fire, and furnishing us with a most valuable pigment, Ultramarine,
more precious than gold!

The analysis of lapis lazuli represented it to be composed of
silica, alumina, and soda, three colourless bodies, with sulphur and
a trace of iron. Nothing could be discovered in it of the nature of
a pigment, nothing to which its blue colour could be referred, the
cause of which was searched for in vain. It might therefore have
been supposed that the analyst was here altogether at fault, and
that at any rate its artificial production must be impossible.
Nevertheless, this has been accomplished, and simply by combining in
the proper proportions, as determined by analysis, silica, alumina,
soda, iron, and sulphur. Thousands of pounds weight are now
manufactured from these ingredients, and this artificial ultramarine
is as beautiful as the natural, while for the price of a single
ounce of the latter we may obtain many pounds of the former.

With the production of artificial lapis lazuli, the formation of
mineral bodies by synthesis ceased to be a scientific problem to the
chemist; he has no longer sufficient interest in it to pursue the
subject. He may now be satisfied that analysis will reveal to him