1 Mar., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 225 
cattle ; others did not injure the cattle, but had little effect upon the ticks. 
Some would kill the greater part of the ticks in winter, but would not do nearly 
so well in summer. During the years 1894 and 1895 more than 20,000 ticky 
cattle were dipped, but none of the dips used would kill all of the ticks without 
injuring the cattle so seriously as to make them inadmissable for general use. 
Dr. Francis, of the Texas Experiment Station, deserves credit for first 
experimenting with an oil dip. While the crude cotton-seed oil which he 
employed did not kill all of the ticks, either when used alone or with the 
addition of as much carbolic acid as the cattle could bear, it was nevertheless a 
step in the right direction. Dr. Francis also experimented with crude black 
mineral oil. Both of these oils were too heating in their effects upon the 
animals. The oil and carbolic acid and the black mineral oil caused extensive 
and serious inflammation of the skin and eyes, and failed to kill all of the ticks. 
Dr. Norgaard, who was stationed*at the Santa Gertrude’s Ranch, and later 
at Fort Worth, experimented with a great variety of oils, emulsions, solutions 
of soap, &ec., and concluded that a lighter kind of “mineral oil, called “ paraffin 
oil,” was most efficient. The irritation of the skin caused ‘by this oil was 
slight, and no heating effect was apparent. After being dipped in crude 
cotton-seed oil, or black mineral oil, the cattie would pant or breathe heavily, 
and show all the symptoms of suffering from extreme heat, even when the 
atmospheric temperature was not above that of ordinary spring or fall weather. 
This was a great disadvantage with cattle that were to be shipped at once, or 
driven, particularly in summer. 
The paraffin oil is a lighter product than the black oil, the volatile irritating 
constituents having been distilled off, and this residue, which is generally used 
for lubricating purposes, should be neutral, bland, and soothing to the skin. 
Although this oil was more efficient as a destroyer of ticks than any substance 
previously used, it was still found that some of these parasites survived, 
particularly the small ticks that were almost ready to moult. Notwithstanding 
this fact, the result was such as to make it evident that this oil must form the 
basis of the coming dip. 
Just at this point in the investigations the dip was a subject of much 
anxiety and long-continued study. Success was so nearly attained that we 
could not endure the thought of failure, and yet just enough ticks managed to 
escape destruction to compel -us still to hold the cattle as dangerous. In 
considering how the efficiency of this oil might be increased, it was always 
necessary to bearin mind the three essentials of a successful dipping mixture : 
first, it must kill all of the ticks; secondly, it must not seriously injure the 
cattle ; and thirdly, it must be of moderate cost. 
By experimenting with this oil it was found that, when hot, it would dissolve 
aconsiderable quantity of sulphur, and that this combination of oil and sulphur 
was much more destructive to the ticks than the oil alone. Previous to this 
time the oil had been used in the form of a layer about 1 foot deep floating 
upon water. That is, as a matter of economy the dipping-vat was nearly filled 
with water, and 1 foot of oil was run in upon the top, where it remained on 
account of being lighter than water. The theory was that the cattle, as they 
dropped into the vat and were submerged, would go entirely through the layer 
of oil and in coming out they must go through this oil a second time, thus 
making it certain that all portions of the skin would receive a coating. 
Observations showed, however, that in dropping the cattle into the liquid a great 
splashing and mixing of the oil and water was caused, which led to some parts 
of the surface of the body being saturated with water before they were touched 
with oil. As a natural consequence, very little oil adhered to those parts where 
the hair was first filled with water. It was therefore decided that the vats 
must be alinost entirely filled with oil, and that not over 1 foot of water could be 
permitted in the bottom of the vat. A small quantity of water is useful for 
collecting the dirt and excrement which finds its way into the vat in considerable 
quantities, and which, when it settles to the bottom, may be drawn off without 
wasting the oil. 
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