164 
vented by the well-known method of shaving off the eggs, so as to pre- 
vent the introduction of the larvie into the mouths, while for the bot 
fly affecting the sheep I am not aware of any more effective plan of pre- 
vention than that of applying tar to the noses of the sheep. For direct 
treatment, the methods for external parasites may be grouped under 
the head of washes, powders, and fumigation. The use of washes in 
the treatment of parasites is perhaps one of the oldest methods. The 
modifications consist in the methods of applying or in the materials 
used asa wash. The method of application will depend somewhat upon 
circumstances, but should aim to reach all parts of the body, and par- 
ticularly those parts most infested. Sponging the animal with a cloth 
or sponge dipped in the insecticide material and application by means 
of force pump in certain cases, particularly for hogs and thin-haired 
animals, is practicable in certain forms. A device recently presented 
by Dr. Francis, of Texas,* provides for the pressure by means of gravity, 
the barrel being elevated on a derrick and connected by hose with 
several nozzles directed downward, and a movable one to use in spray- 
ing the under parts of the body, the liquid being collected from a drip 
platform in a receptacle below. The liquid, however, is elevated by a 
pump, and while it may lessen the number of men necessary in spray- 
ing, the same end can easily be accomplished where a force pump is at 
hand, if it is connected with several nozzles adjusted so as to play at 
proper angles on the animal. Dipping is probably the most speedy 
and ettective method to use on a large scale, and especially for thick- 
haired or woolly animals, and for this purpose receptacles ranging all 
the way from a small tank for the treatment of a single animal at a 
time up to a large tank, including two or three dozen sheep at once, 
may be used. The ingredients for these washes have consisted mainly 
of tobacco, sulphur, lime, tar, kerosene, and arsenic, and each of these 
materials will be found to have its advocates. 
Special formule for their combinations have been published in abun- 
dance, and need not be repeated here. Aside from these published for- 
mule there are different preparations on the market, some of which are 
doubtless valuable, and if the item of expense is considered satisfae- 
tory, itis perhaps proper to recommend their use. Kerosene emulsion 
has been used with success by Prof. Gillettet on cattle and hogs, and 
by Dr. Orcutt and Mr. Aldricht for sheep dip, but Prof. Francis pro- 
nouncees it less satisfactory than some of the proprietary combinations. 
for ticks on cattle. I have also seen some reports of poor success with 
it or apparent injury, especially to lambs, from its use. 
While I fully believe in its efficiency when properly made and 
applied and would attribute failures to improper preparation, the fact 
* Bulletin Texas Ag. Exp. Sta., No. 24, p. 256.. 
t South Dakota Exp. Sta. Bulletin No. 30, pp. 16, 17. 
{ lowa Exp. Sta. Bulletin No. 11, p. 495. 
ed 
