es, and scorched and
half suffocated by the fiery pestilential vapor, is to experience very
peculiar sensations, such as one feels within the crater of Vesuvius or
AEtna, or in the obscurity of the Grotto del Cave.

Another lagoon is scooped out lower down the mountain, the site being
determined by the occurrence of soffioni; and here the same processes
are followed, and the same phenomena observable. The water from the
lagoon above, after it has received impregnation during twenty-four
hours, is let off, and conducted by an artificial channel to the second
lagoon; and from thence, with similar precautions, to a third, a fourth,
and so on, till it at length reaches a sixth or eighth lagoon, where the
process of impregnation is supposed to be completed. By this time the
water contains half per cent, of acid, which Professor Gazzeri
considered far too little to repay the expense of extracting it. From
the last lagoon it is conveyed into reservoirs, whence again, after
having remained quiescent a few hours, for what purpose is not stated,
it passes into the evaporating pans. "Here the hot vapor concentrates
the strength of the acid by passing under shallow leaden vessels from
the boiling fountains above, which it quits at a heat of 80 degrees
Reaumur, and is discharged at a heat of 60 degrees (101 Fahrenheit)."

The evaporating pans are arranged on the same principles as the lagoons,
though in some cases almost four times as numerous, each placed on a
lower level than the other. In every successive pan the condensation
becomes greater. All the water at length descends into the
crystallizing vessels, where the process is completed. From these the
borax is conveyed to the drying-rooms, where in the course of a very few
hours, it is ready to be packed for exportation. The number of
establishments has for many years been on the increase, though about
twelve or fourteen years ago they did not exceed nine. Nothing can be
more fallacious than the opinions formed by hasty visitors on matters of
this kind, which are susceptible of perpetual improvement. When the
produce was from 7000 to 8000 Tuscan pounds per day, the manufacturers
were supposed to have reached the maximum, because all the water of the
mountains was supposed to have been called into requisition. Experience,
however, is perpetually teaching us new methods of economy; and though
it would _a priori_ be impossible to say by what means this economy is
to be effected, w