simpler, and cheaper methods of making it were discovered. With
every improvement in the mode of manufacture, its price fell; and
its sale increased in an equal ratio.

Sulphuric acid is now manufactured in leaden chambers, of such
magnitude that they would contain the whole of an ordinary-sized
house. As regards the process and the apparatus, this manufacture
has reached its acme--scarcely is either susceptible of improvement.
The leaden plates of which the chambers are constructed, requiring
to be joined together with lead (since tin or solder would be acted
on by the acid), this process was, until lately, as expensive as the
plates themselves; but now, by means of the oxy-hydrogen blowpipe,
the plates are cemented together at their edges by mere fusion,
without the intervention of any kind of solder.

And then, as to the process: according to theory, 100 pounds weight
of sulphur ought to produce 306 pounds of sulphuric acid; in
practice 300 pounds are actually obtained; the amount of loss is
therefore too insignificant for consideration.

Again; saltpetre being indispensable in making sulphuric acid, the
commercial value of that salt had formerly an important influence
upon its price. It is true that 100 pounds of saltpetre only are
required to 1000 pounds of sulphur; but its cost was four times
greater than an equal weight of the latter.

Travellers had observed near the small seaport of Yquiqui, in the
district of Atacama, in Peru, an efflorescence covering the ground
over extensive districts. This was found to consist principally of
nitrate of soda. Advantage was quickly taken of this discovery. The