Year: 1871

LACoUERING VARNIsH.-A varnish re-
commended as we'll adapted for lacquer
ing pictures and engravings, as we'll as
for preserving dried plants and flowers,
is prepared by pounding up ten ounces
of gum Sandarac, four ounces of maStic,
and half ar ounce of camphor, and add
ing three quarts of strong alcohol. The
mass is to be frequently shaken up, and
finally placed in a warm situation until
it settles. Plants coated with this var
nish will, it is said, be protected from
destruction by insects, and will retain
their color fresh and unchanged. This
varnish does not peel off, and, therefore,
can be applied very thin.


GALVANIZED IRoN.-A method of es-
timating the quantity of zinc existing
in the plating of galvanized iron has
Magazine by Mr.. T. Warren. The prin-
ciple of this method consists in the use
of mercury to dissolve the zinc, when
the loss of weight can be easily ascer-
tanned. But thin coating of an ANAL
gam of iron and zinc will remain, which
will take up certain quantity of mer-
curry, and the amount of this amalgam
mercury it will take up. To determine
this quantity of mercury, the iron is
weighed, then heated to drive the mer-
curry off, and then weighed again, when
the weight of mercury which has mixed
with the amalgam will be at once ascer-
tanned.


The manufacture OF gun cotton has
been so much improved that it is more
and more used for quarrying, mining
and military purposes. The cotton is
now made in compressed form, which
can be handled and transported with
safety, and can be exploded by detona-
ton only. If set on fire without deto-
nation, it burns away harmlessly. This
fact is generally in favor of increasing
its use. About one hundred tons of the
cotton are now sold yearly for blasting
in quarrieS and mineS-a quantity equal
to at least five hundred tons of gunpow-
der. In the slate quarries in Wales it is
largely employed; and there and in the
mines the workmen find the advantage
of having no smoke after blast.


ANOTHER NEW CEMENT.-Among the
novelties recently introduced, is a new
cement in imitation of marble. 1t is
well known that cement, partly COM
posed of marble dust, was used by the
ancients in coating the columns and
walls of their buildings. 1t is found in
Italy and other genial climes, to be not
inferior to their native marble on expos
ure to the effects of the atmosphere.
The cement now under notice does not,
however, contain any portion of marble
dust, but is composed of gypsum de-
prived of its water of crystalization by
great heat, and is then saturated with
solution of alum of proper strength.
The mixture being then subjected to in
tense heat, is equal in durability and ca
pability of polish and color to the finest
maj BILE. Sulphate of alum, being the
base on which most colors were struck,
and alum the mordant used to fix them
affords sufficient proof of the aptitude
of the cement to receive any of the COL
ors in imitation of m arbles, granite
woods. etc.


SMOKING AS A SURGICAL APPLIANCE.
Smoking is so evidently on the increase
that the Food Journal thinks it highly
desirable to dispel all ignorance upon
the subject, and so far popularize all es-
sential facts peculiar to tobacco as to re-
duce such of its effects as are injurious
to the human organism in the minimum.
"Long known as prophylatic," says
that journal, Fsthe dreadful war on the
continent has revealed in tobacco a quail
ity which renders it very fair anees-
thetic. The soothing cigar has come to
be natural sequence to the cruel knife
in army surgery, and it is now notorious
that the eX-Emperor of the French de-
rived no small part of his political safe
ty previous to the war from the simple
circumstance that he carefully supplied
the army with large allowances of good
tobacco privilege that was highly ap-
preciatedo