94 EXTERMINATING THE TEXAS-FEVER TICK. 
The diluted arsenical solution may be left in the vat and used 
repeatedly, replenishing with the proper quantities of water and stock 
solution when necessary. When not in use the vat should be tightly 
covered with a waterproof cover to prevent evaporation on the one 
hand and further dilution by rain on the other hand. Securely 
covering the vat when not in use also lessens the risk of accidental 
poisoning of stock and human beings. 
Precautions in use of arsenic.—On account of the fact that arsenic is a 
dangerous poison, great care must be observed in making and using the 
arsenical dip. From the time the arsenic is procured from the druggist 
until the last particle of unused residue is properly disposed of, the most 
scrupulous care should be taken in handling this poison. Guessing at 
weights or measures or carelessness in any particular is liable to result in 
great damage, and not only may valuable live stock be destroyed, but 
human beings may lose their lives as well. 
In the use of arsenical dips care should be taken not only to avoid swal- 
lowing any of the dip, but persons using the dip should also bear in mind 
the possibility of absorbing arsenic through cuts, scratches, or abrasions of 
the skin, and the possibility of absorbing arsenic by inhalatioa of vapors 
from the boiler in which the dip is prepared, or by the inhalation of the 
finely divided spray when the spray pump is used. It should be remem- 
bered that the absorption of even very small quantities of arsenic if 
repeated from day to day is liable ultimately to result in arsenical poisoning. 
Cattle should always be watered a short time before they are dipped. 
After they emerge from the vat they should be kept on a draining floor until 
the dip ceases to run from their bodies ; then they should be placed in a yard 
free of vegetation until they are entirely dry. If cattle are allowed to 
drain in places where pools of dip collect, from which they may drink, or are 
turned at once on the pasture, where the dip will run from their bodies on the 
grass and other vegetation, serious losses are liable to result. Crowding 
the animals before they are dry should also be avoided, and they should not 
be driven any considerable distance within a week after dipping, espe- 
cially in hot weather. If many repeated treatments are given the cattle 
should not be treated oftener than every two weeks. 
In addition to properly protecting vats containing arsenical dip when 
not in use, another precaution must be observed when vats are to be 
emptied for cleaning. The dip should not be poured or allowed to flow on 
land and vegetation to which cattle or other animals have access. The 
best plan is to run the dip in a pit properly protected by fences. 
The dip should also not be deposited where it may be carried by seepage 
into wells or springs which supply water used onthe farm. The same pre- 
cautions should be observed when animals are sprayed as when they are 
dipped. 
Method of spraying.—Spraying is probably the most practicable 
and convenient way of treating cattle on the majority of farms. A 
378 
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