ts, without disturbing the settlings, and the part so poured
off contains only the finest of the emery particles, and is the only
part which should be used on the lapping roller.

EXPLOSIVES.--Common Gunpowder. Potassium nitrate, 75 parts; charcoal, 15
parts; sulphur, 10 parts.

Dynamite. 75 per cent. nitro-glycerine; 25 per cent. infusorial earth.

Giant Powder. 36 per cent. nitro-glycerine; 48 per cent. nitrate of
potash; 8 per cent. of sulphur; 8 per cent. charcoal.

Fulminate. Chlorate of potassia, 6 parts; pure lampblack, 4 parts;
sulphur, 1 part. A blow will cause it to explode.

FILES.--How to Keep Clean. Olive oil is the proper substance to rub over
files, as this will prevent the creases from filling up while in use,
and preserve the file for a longer time, and also enable it to do better
cutting.

To Renew Old Files. Use a potash bath for boiling them in, and
afterwards brush them well so as to get the creases clean. Then stretch
a cotton cloth between two supports, and after plunging the file into
nitric acid, use the stretched cloth to wipe off the acid. The object is
to remove the acid from the ridges of the file, so the acid will only
eat out or etch the deep portions between the ridges, and not affect the
edges or teeth.

FIRE PROOF MATERIALS OR SUBSTANCES.--For Wood. For the kind where it is
desired to apply with a brush, use 100 parts sodium silicate; 50 parts
of Spanish white, and 100 parts of glue. It must be applied hot.

Another good preparation is made as follows: Sodium silicate, 350 parts;
asbestos, powdered, 350 parts; and boiling water 1,000 parts.

For Coating Steel, etc. Silica, 50 parts; plastic fire clay, 10 parts;
ball clay, 3 parts. To be thoroughly mixed.

For Paper. Ammonium sulphate, 8 parts; boracic acid, 3 parts; borax, 2
parts; water, 100 parts. This is applied in a liquid state to the paper
surface.

FLOOR DRESSINGS.--Oil Stain. Neats' foot oil, 1 part; cottonseed oil, 1
part; petroleum oil, 1 part. This may be colored with anything desired,
like burnt sienna, annatto, or other coloring material.

Ballroom Powder. Hard paraffine, 1 pound; powdered boric acid, 7 pounds;
oil of lavender, 1 drachm; oil of neroli, 20 minims.

FOOT POWDERS.--For Perspiring Feet. Balsam Peru, 15 minims; formic
acid, 1 drachm; chloral hydrate, 1 drachm; alcohol to make 3 ounces.

For Easing Feet. Tannaform, 1 drachm; talcum, 2 drachms; lycopodium, 30
grains.

Frost Bites. Carbolized wate