Black Ink

The chemicals required to make one gallon of best black ink are: Nigrosine, " P." 1 1/2 oz.

Methilyne Blue, 3° 1/4 oz.

To one quart of water, either hot or cold, add the Nigrosine; stir well. To a small quantity of water, add the Methilyne Blue; stir well. Add both solutions together, mixing thoroughly; add enough water to make one gallon. The cost for the above quantity of chemicals is about 25 cents. This formula is in use in many schools throughout the country, and the ink gives excellent satisfaction.

Colorless Varnish

Colorless varnish for use on fine labels or other prints, as well as for whitewood and other spotless articles, is made as follows: - Dissolve 2 1/2 oz. of bleached shellac in one pint of rectified alchohol; to this add 5 oz. of animal boneblack, which should first be heated, and then boil the mixture for about five minutes, filter a small quantity of this through filtering paper and if not fully colorless add more bone-black and boil again. When this has been done, run the mixture through silk and through filtering paper. When cool, it is ready for use. It should be applied with care and uniformity.

Reviving Weak Dry Batteries

Old dry batteries, the current of which has become two weak for use, may be revived by punchihg several holes through the covering of hard pitch on the top, and allowing a solution of sal-ammoniac, or common salt and water, to soak into the cells.

Another way is to punch numerous holes in the sides, place them in glass preserve jars, filling the jars two thirds full of the solution. Considerable additional service may be obtained from cells thus treated, provided they are used where the liquid is not objectionable.