The many diseases of farm live-stock cannot be treated in a book of this kind, and very brief advice might be more dangerous than useful; but the ticks, lice, fleas, and similar things that infest animals may be included. The spraying of live-stock is as important, in many cases, as the spraying of plants.

Handling the cattle-tick, or Texas-fever tick (Margaropus annulatus) (H. W. Graybill, Bur. Animal Ind., U. S. Dept. Agric.)

On the pasture there are three stages of the tick — the engorged female, the egg, and the larva ; and on the host are four stages — the larva, the nymph, the sexually mature adult of both sexes, and the engorged condition of the female.

Animals may be freed of ticks in two ways. They may be treated with an agent that will destroy all the ticks present, or they may be rotated at proper intervals on tick-free fields until all the ticks have dropped.

Dips for cattle-ticks, their preparation and use

Crude petroleum. — Various kinds of crude petroleum have been used with more or less success in destroying ticks. The heavier varieties of oil are very injurious to cattle. On the other hand, the very light oils are so volatile that their effect lasts but a short time thus rendering them less efficient. The petroleum known as Beaumont oil, obtained from Texas wells, has given the best results. The best grade of this oil to use is one that has a specific gravity ranging from 22 1/2° to 241/2° Beaume, containing 11/4 to 11/2 per cent of sulfur, and 40 per cent of the bulk of which boils between 200° and 300° C. The oil may be applied by employing a spray pump or a dipping vat.

Animals that have been dipped in crude oil, especially during warm weather, should not be driven any great distance immediately afterwards, and should be provided with shade and an abundance of water. Unless these precautions are observed serious injury and losses may result.

Emulsions of crude petroleum. — In the majority of cases the best agent to use is an emulsion of crude petroleum, preferably Beaumont crude petroleum. The use of the emulsion makes the treatment less expensive than when the oil alone is used. The emulsion is not so injurious to the cattle and is almost if not quite as effective as the oil alone. The formula for preparing an emulsion of crude petroleum is as follows : —

Hard soap.....................1 lb.

Soft or freestone water.................1 gal.

Beaumont crude petroleum...............4 gal.

Making five gallons of 80 per cent stock emulsion.

When a greater quantity of stock emulsion is desired, each of the quantities in the above formula should be multiplied by such a number as to furnish the required amount. For example, if it should be convenient to mix 10 gallons at one time, the quantities would have to be multiplied by 2 and if 15 gallons were desired, they would have to be multiplied by 3, and so on.

In preparing the emulsion the soap should be shaved up and placed in a kettle or caldron containing the required amount of water. The water should be brought to a boil and stirred until the soap is entirely dissolved. Enough water should be added to make up for the loss by evaporation during this process. The soap solution and the required amount of oil are then placed in a barrel or some other convenient receptacle, and mixed. The mixing may be effected by the use of a spray pump, pumping the mixture through and through the pump until the emulsion is formed. A convenient and time-saving method is to do the mixing in a barrel by first pouring in one part of hot soap solution and then four parts of crude petroleum, and repeating this until the barrel is filled. The oil should be poured in with as much force as possible, and the mixture stirred constantly with a long paddle until the oil is completely emulsified. The mixing is facilitated also by dipping up the mixture and pouring it back with a pail. If made properly, this stock emulsion is permanent, and will keep indefinitely.