the sewer.
Occasionally when copper and silver have accumulated in E in
sufficient amount the mass is thrown into D, silver sulphate crystals
are added and sheet copper is thrown in, instead of sheet iron. There
results a hot, neutral, concentrated solution of copper sulphate,
which may be run at once into a crystallizing vat for the separation
of commercial crystals of copper sulphate. It will be readily
understood, of course, that if there should be any advantage in
manufacturing that commercial article, besides the amount prepared as
described, which represents merely the copper contained in the
bullion, copper sheets may be regularly employed for reducing the
silver sulphate in D. The author trusts that the practical refiner
will recognize that the manufacture of commercial copper sulphate is
thus effected in a more rational and economical manner than by the
present method of evaporating from 25 deg. B. to 35 deg. B., and of saturating
by oxidized copper, generally in a very incomplete manner, the large
amount of free acid left from the refining by the usual process.
However, the sale of copper sulphate is but rarely so profitable that
a refinery should not gladly dispense with that troublesome and bulky
manufacture, especially the government establishments, which, besides,
waste much valuable space with the crystallizing vats.

The great saving in sulphuric acid, amounting to about 50 per cent. of
the present consumption, has already been pointed out. Another
advantage the author merely mentions, namely, the easier condensation
of the sulphurous fumes in refineries situated in cities, because the
larger amount of acid available for dissolving greatly facilitates
working and makes the usual frequent admission of air into the
refining pot for the purpose of stirring and testing unnecessary.

The more air is excluded from the refining fumes the easier they can
be condensed.

Work may be carried on continuously, the vessels C and D being empty
by the time a new solution is finished in A A. Thus, the plant shown
in the diagram, covering 26 ft. by 16 ft., allows the refining of
40,000 ounces of fine silver in 24 hours; that is, four charges in A A
of 800 pounds each.--_F. Gutzkow, Eng. and Mining J._

* * * * *

A CASE OF DROWNING, WITH RESUSCITATION.

By F.A. BURRALL, M.D., New York.

As is usual at this season, casualties from drowning are of frequent
occurrence. No clas