EXTERMINATING THE TEXAS-FEVER TICK. 21 
out of an infestation will be effected when begun at various times 
of the year have already been given in the table on page 11. In 
actual practice, however, the best treatment will in many cases 
not be absolutely successful, as some ticks will escape and may 
reinfest the pasture and thus prolong the time necessary to accom- 
plish eradication. This method offers the advantage that the pasture 
may be used continuously. 
Dips, their preparation and use.—Crude petrolewm.—Various kinds 
of crude petroleum have been used with more or less success in destroy- 
ing ticks. The heavier varieties of oil are very injurious to cattle. 
On the other hand, the very light oils are so volatile that their effects 
last but a short time, thus rendering them less efficient. The petro- 
leum 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 225° to 243° Beaumé, containing 1} to 
14 per cent of sulphur, 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 after- 
wards, 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 petrolewm.—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: 
LSE [SDN 0 RE SS Oe hee a ge ee ee eee Be pound.. 1 
SOMiOrImeegtONe walelsascsece a c.2 sone coe Seis ke oc see Sees gallon.. 1 
beapmont crude petroleums: 5 s.-..2oss4. 4422s. e60.264.-'42 gallons... 4 
Making 5 gallons of 80 per cent steck 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. Jor example, if it should be con- 
venient 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 
378 
