methods have
been proposed for dealing with the waste products arising during the
manufacture and manipulation of fulminate of mercury, but according to
Kaemmerer, only one of comparatively recent introduction appears to be at
all satisfactory. It is based upon the fact that mercuric fulminate, when
heated with a large volume of water under high pressure, splits up into
metallic mercury and non-explosive mercurial compounds of unknown
composition.

In mixing the various ingredients with mercury fulminate to form cap
mixtures, they should not be too dry; in fact, they are generally more or
less wet, and mixed in small quantities at a time, in a special house, the
floors of which are covered with carpet, and the tables with felt. Felt
shoes are also worn by the workpeople employed. All the tools and
apparatus used must be kept very clean; for granulating, hair sieves are
used, and the granulated mixture is afterwards dried on light frames, with
canvas trays the bottoms of which are covered with thin paper, and the
frames fitted with indiarubber cushions, to reduce any jars they may
receive. The windows of the building should be painted white to keep out
the rays of the sun.

Mr H. Maxim, of New York, has lately patented a composition for detonators
for use with high explosives, which can also be thrown from ordnance in
considerable quantities with safety. The composition is prepared as
follows:--Nitro-glycerine is thickened with pyroxyline to the consistency
of raw rubber. This is done by employing about 75 to 85 per cent. of
nitro-glycerine, and 15 to 25 per cent. of pyroxyline, according to the
stiffness or elasticity of the compound desired. Some solvent that
dissolves the nitro-cotton is also used. The product thus formed is a kind
of blasting gelatine, and should be in a pasty condition, in order that it
may be mixed with fulminate of mercury. The solvent used is acetone, and
the quantity of fulminate is between 75 to 85 per cent. of the entire
compound. If desired, the compound can be made less sensitive to shocks by
giving it a spongy consistency by agitating it with air while it is still
in a syrupy condition. The nitro-glycerine, especially in this latter
case, may be omitted. In some cases, when it is desirable to add a
deterring medium, nitro-benzene or some suitable gum is added.

[Illustration: FIG. 34. METHOD OF PREPARING THE CHARGE.]

The method of preparing a blasting charge is as follows:--A piece of