ch, under the
extreme influence of our climate, rapidly deteriorate; such, for
instance, as the Connecticut sandstone, so popular at one time as a
building material, but which is now generally discarded, owing to its
tendency to crumble to pieces when exposed to the weather even for a few
years.

Soluble glass has also been used in Germany to a great extent for mural
painting, known as stereochromy. The process consists in first laying a
ground with a lime water; when this is thoroughly dry, it is soaked with
a solution of silicate of soda. When this has completely solidified, the
upper coating is applied to the thickness of about one-sixteenth of an
inch, and should be put on very evenly. It is then rubbed with fine
sandstone to roughen the surface. When thoroughly dry, the colors are
applied with water; the wall is also frequently sprinkled with water. The
colors are now set by using a mixture of silicate of potash completely
saturated with silica, with a basic silicate of soda (a flint liquor with
soda base, obtained by melting 2 parts sand with 3 parts of carbonate of
soda). As the colors applied do not stand the action of the brush, the
soluble glass is projected against the wall by means of a spray. After a
few days the walls should be washed with alcohol to remove the dust and
alkali liberated.

The colors used for this style of painting are zinc white, green oxide
of chrome, cobalt green, chromate of lead, colcothar, ochers, and
ultramarine.

Soluble glass has also been used in the manufacture of soaps made with
palm and cocoanut oil; this body renders them more alkaline and harder.

Interesting experiments have been made with soluble glass for coloring
corals and shells. By plunging silicated shells into hot solutions of
salts of chrome, nickel, cobalt, or copper, beautiful dyes in yellow,
green, and blue are produced. Here seems to be a field for further
application of this discovery.

Soluble glass has also been applied to painting on glass in imitation of
glass staining. By using sulphate of baryta, ultramarine, oxide of
chrome, etc., mixed with silicate of potash, fast colors are obtained
similar to the semi-transparent colors of painted windows. By this means
a variety of cheap painted glass may be made. Should these colors be
fired in a furnace, enameled surfaces would be produced. As a substitute
for albumen for fixing colors in calico printing, soluble glass has been
used with a certain degree of