LABORATORY EQUIPMENT FOR CHEMISTRY


 b. Desks. In the emergency, any table will do. A more
useful desk, easily constructed, is in the form of a "picnic table,"
made of smooth boards. The top should be 4 feet wide, 36 inches
high, and any convenient length. Pupils work standing on both
sides of this table. You would supply apparatus to them as
needed out of your stock, and require its return, thoroughly
cleaned, at the end of the period.
 Individual lockers under each desk will cost more to build
and require more apparatus to fill them. They are time savers
for both pupils and teacher; but it is money, and not time, that
you will lack next year.
 Even this simple desk should be painted, or varnished, accord-
ing to your taste, and the top made acid proof by treatment with
the following solutions:
 Solution 1. 125 grams (1/3 cupful) of copper sulfate crystals
 125 grams (1/2 cupful) of potassium chlorate crystals
 1 liter (1 quart) of water.
 Solution 2. 150 grams (2/3 cupful) of aniline oil
 180 grams (3/4 cupful) of concentrated hydrochloric
 acid
 1 liter (1 quart) water.
 The wood should be free from paint, varnish, or grease. Apply
two coats of Solution 1, boiling hot, with a paint brush, then
two coats of Solution 2 in the same way. Let each coat dry be-
fore adding the next. Wash off the excess chemicals with hot
soapsuds. Be careful not to get them on the floor, for the stain
will not be easily removed. Now rub with a coating of linseed
oil. Vigorous persistence is needed at this point. When rubbed
thoroughly dry, a highly polished black surface is left, which
will resist all chemicals and will not turn greasy with heat.
 The desk tops may be kept polished like a piano by the weekly
use of a suitable polish. A supply which will last for a year may
be made by melting five pounds of beeswax in a pan, removing
from the flame, and pouring spirits of turpentine into the mix-
ture, with stirring, until a little of the hot liquid, dipped out
with a spoon and held under water, will harden to a sticky paste.
The warm polish should then be poured into fruit jars and kept
tightly covered to prevent drying. Do not use too much on the