38 BOARD OF AGRICULTURE. 
The various species of these lice have similar habits, and allare 
blood suckers, but each species inhabits only certain kinds of 
animals, and some are restricted to particular parts of the 
skin. Many animals have two or more species of these para- 
sites. Five species have been described as parasitic upon man, © 
though but three are common. . 
When they become very abundant, as they soon will if the 
animals upon which they once get well established be neg- 
lected, they cause great irritation of the skin and nervous | 
system, and the itching that they produce causes the animals 
to rub themselves against buildings, fences, etc., and thus the 
hair is often worn off and the skin abraded. Such animals 
generally soon become weak and emaciated, and are, there- 
fore, more liable to be attacked by other diseases. 
There are various washes which, if properly applied, will 
very rapidly destroy all species of lice, without much trouble. 
The use of preparations of mercury and arsenic, and all similar 
poisons, should be avoided, for they often poison the animals, 
as well as the persons who use them, and thus the remedy 
may be worse than the disease. 
A strong solution of tobacco, made by boiling cheap tobacco 
in water, is an effectual remedy, in common use. Snuff 
rubbed into the hair isalso used. Ordinary whale-oil, such as 
was formerly used in lamps, poured upon the skin along the 
back of an ox, cow, calf, or sheep, will diffuse itself over the 
skin and kill the lice. Weak petroleum water, or carbolic 
acid solution, or carbolic soap, may be used as a wash, or 
small animals may be immersed in a bath, taking care to 
keep the nose, mouth, and eyes outof it. But perhaps one of 
the best and simplest, as well as safest, washes for this pur- 
pose, as well as to destroy fleas, mites, itch-insects, mange- 
acari, and all other external parasites of man and animals, is 
a solution of sulphuret of potassiwm in water,—two to four 
ounces to the gallon of cold water, varying the strength ac- 
cording to the age and tenderness of the skin of the animal, 
for the solution will contain some free potash, which, if too 
strong, might irritate a delicate skin. There is otherwise no 
danger from its use, though its odor, like sulphuretted hydro- 
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