The insecticides.

Following are the leading insecticidal substances used against fleas, lice, ticks, and other pests of farm live-stock: —

Lime-and-sulfur dip.

Unslaked lime................... 8 lb.

Flowers of sulfur..................24 lb.

Water......................100 gal.

Slake the lime in a little water and add the sulfur, stirring constantly. Transfer the mass to 25 gallons of hot water, and boil for two hours, adding water to replace that boiled away. Let the solution stand until all sediment has settled and then draw off the clear liquid and dilute to 100 gallons. (U. S. Bureau of Animal Industry.)

Nicotine solutions. — There are now on the market nicotine solutions with a guaranteed strength of from 5 to 40 per cent of nicotine. For use they should be so diluted as to give a solution containing 5/100 of 1 per cent of nicotine, and 161/2 pounds of flowers of sulfur should be added to each 100 gallons of the liquid.

Eradication of ticks by rotation of fields (Graybill.)

Other External Parasites of Farm Animals Crosby 166

Fig. 13. - Rotation plan for freeing plantation in South from ticks in 41/2 mos.

Other External Parasites of Farm Animals Crosby 167

Fig. 15. - Plan requiring 8 mos.

Other External Parasites of Farm Animals Crosby 168

Fig. 14. - Plan requiring 4 mos., with new pasture.

Other External Parasites of Farm Animals Crosby 169

Fig. 16. - Feed-lot or soiling method of elin nating ticks.

Commercial dips. — There are a large number of these proprietary dips on the market, many of which contain as the active agent coal-tar derivatives. Use only those that have the approval of the United States Department of Agriculture, and follow closely the directions given on the container.

Crude oil emulsion (for spraying stock).

Soap.......................1 lb.

Crude oil.....................4 gal.

Water......................1 gal.

Dissolve the soap in hot water, and while still hot add the oil slowly and agitate into an emulsion by pumping the mixture back into itself. For use, dilute with water so as to secure a 20 or 30 per cent emulsion (see p. 430).

Lice powder.

Gasoline.....................3 parts

Crude carbolic acid (90-95 per cent strength).........1 part

Mix these together, and then stir in enough plaster of Paris to take up all the moisture. If properly made, a dry pinkish powder will be the result. If good crude carbolic acid of the proper strength cannot be obtained, cresol may be substituted, but will not give quite as good results.

Cresol disinfecting soap. — Measure out 31/5 quarts of raw linseed oil in a four or five-gallon stone crock ; then weigh out in a dish 1 pound 6 ounces of commercial lye or " Babbit's potash." Dissolve this lye in as little water as will completely dissolve it. Start with 1/2 pint of water, and if this will not dissolve all the lye, add more water slowly. Let this stand for at least three hours until the lye is completely dissolved and the solution is cold ; then add the cold lye solution very slowly to the linseed oil, stirring constantly. Not less than five minutes should be taken for the adding of this solution of lye to the oil. After the lye is added, continue the stirring until the mixture is in the condition and has the texture of a smooth, homogeneous liquid soap. This ought not to take more than a half hour. Then, while the soap is in this liquid state, and before it has a chance to harden, add with constant stirring, 81/2 quarts of commercial cresol. The cresol will blend perfectly with the soap solution and make a clear, dark brown fluid. The resulting solution of cresol soap is then ready to use. This cresol soap will mix in any proportion with water and yield a clear solution. Use a 20 per cent solution for disinfecting chicken houses, incubators, etc.