(368 The Diseases of Animals 
neck or shoulder. In case the latter place is chosen, care 
should be taken not to push the needle into the mus- 
cles, but simply into the loose tissue beneath the skin. 
The single vaccines should be used in the tail, to insure 
safety. Vaccine should not be kept more than an hour 
or two after mixing, and then only in a clean, well- 
stoppered bottle. Vaccinating instruments, with the 
necessary accessories, can be purchased at from $3.50 
to $5.00. Before using, the instruments should be 
thoroughly cleaned with boiling water, and this precau- 
tion should be repeated just after using. Any cotton or 
filter paper which contains sediment should be burned. 
In using the double method, the second vaccine should 
be prepared as already described, and injected about ten 
days after the first vaccination. 
Vaccination will ordinarily protect cattle for one year, 
although calves under eight months old should be re- 
vaccinated, if possible, when they are yearlings. The 
best time to vaccinate cattle is before they are turned on 
grass in the spring, or just before they are placed on 
dry feed in the fall. Avoid extremes of weather when 
vaccinating, as well as in branding or other surgical 
operations that are likely to lessen the vitality of the 
animal. If the cattle can be confined in a narrow stall, 
cr, better, in a narrow chute, with a little practice a 
hundred head an hour can be vaccinated. There are no 
visible effects from vaccination, if the operation is care- 
fully performed. Full directions for use accompany all 
the vaccines that are on the market. 
A medicine that is used as a preventive of blackleg 
in some parts of the West is as follows: 
