containers, and the glass bottles, porcelain, rubber, or glazed
earthenware may be used.

In mixing acid with water, pour the water in the bottle, pitcher or
jar, and then add the acid to the water very slowly. Do not pour the
acid in quickly, as the mixture will become very hot, and may throw
spray in your face and eyes and cause severe burns. Never add the
water to the acid, as this might cause an explosion and burn your face
and eyes seriously. Stir the mixture thoroughly with a wooden paddle
while adding the acid. A graduate, such as is used in photography, is
very useful in measuring out the quantities of acid and water. The
graduate may be obtained in any size up to 64 ounces, or two quarts.
In using the graduate for measuring both acid and water, be sure to
use the following table giving the parts of water by volume. Although
the graduate is marked in ounces, it is for ounces of water only. If,
for instance, the graduate were filled to the 8 ounce mark with acid,
there would be more than eight ounces of acid in the graduate because
the acid is heavier than the water. But if the proportions of acid and
water are taken by volume, the graduate may be used.

A convenient method in making up electrolyte, is to have a 16 ounce
graduate for the acid, and a 32 or 64 ounce graduate for the water. In
the larger graduate pour the water up to the correct mark. In the 16
ounce graduate, pour 1.400 acid up to the 10 ounce mark. Then add the
acid directly to the water in the graduate, or else pour the water
into a bottle or pitcher, and add the acid to that. For instance, if
we have a 32 ounce graduate, and wish to make up some 1.280 acid, we
fill this graduate with water up to the 5-1/2 ounce mark. We then fill
the 16 ounce graduate with 1.400 acid up to the 10 ounce mark. Then we
slowly pour the 1.400 acid into the graduate containing the water,
giving us 1.280 acid. In a similar manner other specific gravities are
obtained, using the same amount of 1.400 acid in each case, but
varying the amount of water according to the figures given in the last
column of the next to the last table.

The following table shows the number of parts of distilled water to
one part of 1.400 specific gravity electrolyte to prepare electrolyte
of various specific gravities. The specific gravity of the mixture
must be taken when the temperature of the mixture is 70 deg. F. If its
temperature varies more than 5 degrees above or below 70 deg.F, ma