furnished for 96 gallons (about 800 pounds) of dip by 1
pound of a 40 per cent solution of nicotin. The formula for this dip would
be: Nicotin, four-tenths of a pound; flowers of sulphur, 16 pounds; water,
96 gallons.

To calculate how much nicotin solution or extract of tobacco should be used
for 96 gallons of water, divide the quantity of nicotin required in the dip
by the proportion of nicotin in the extract. For example, suppose the
nicotin solution contains 25 per cent nicotin, we have 0.40 / 0.25 = 1.6.
Therefore in this case it would require 1.6 pounds of nicotin solution for
the 96 gallons of dip. Or, if a tobacco extract is used, having, for
example, 2.4 per cent of nicotin, the formula would be as follows: 0.40 /
0.024 = 16.66, and therefore 16.66 pounds would be required for 96 gallons
of dip. Do not use any preparation the strength of which is not given on
the outside of the package.

In preparing these dips the nicotin solution and sulphur should be mixed
together with water before adding them to the water in the dipping vat. On
no account should the dip be heated above 110 deg. F. after the nicotin
solution is added, as heat is liable to evaporate the nicotin and weaken
the dip.

For official dippings the dipping bath should be used at a temperature of
100 deg. to 105 deg. F. and at all times must be maintained at a strength of not
less than five one-hundredths of 1 per cent nicotin as indicated by a field
test approved by the Bureau of Animal Industry.

A homemade nicotin dip may be prepared as follows:

For each 100 gallons of dip desired, take 21 pounds of good, prepared
tobacco leaves; soak the leaves in cold or lukewarm water for 24 hours in a
covered pot or kettle; then bring the water to near the boiling point for a
moment, and, if in the morning, allow the infusion to draw for an hour; if
in the evening, allow it to draw overnight; the liquid is next strained
(pressure being used to extract as much nicotin as possible from the wet
leaves) and diluted to 100 gallons per 21 pounds of tobacco. This dip
should be used as fresh as possible, as it contains a large amount of
organic material which will soon decompose.

CRUDE-PETROLEUM DIPS.

Crude-petroleum dips, which are valuable for the treatment of sarcoptic
mange, are not often used for the treatment of psoroptic mange or of
chorioptic mange, oily dips being liable to injure animals, especially if
they are moved rapidly soon after treatment