THE INOCULATION OF ANIMALS. 239 
greatest care as to cleanliness, the hair being clipped 
and the skin partially, at least, disinfected. After the 
inoculations the animals should be given the best of 
care, unless, for special purposes, we want to study 
them under unusual conditions. For food, rabbits 
and guinea-pigs require only carrots and hay. 
If animals die, autopsy should be made at the earliest 
moment possible, for soon after death some of the spe- 
cies of the bacteria in the intestines are able to penetrate 
through the intestinal walls and infect the body tissues. 
If delay is unavoidable, the animals should be placed 
immediately in a cold place. In making cultures from 
the dead bodies the greatest care should be taken to 
avoid contamination. The skin should be disinfected, 
and any dust prevented by means of a 5 per cent. solu- 
tion of carbolic acid. All instruments are sterilized 
by boiling in 3 per cent. soda solution for five minutes. 
- Changes of knives should be made as frequently as the 
old ones become infected. When organs are examined 
the portion of the surface through which an incision is 
to be made must be sterilized, if there is danger that 
the surrounding cavity is infected, by searing with the 
flat blade of an iron spatula which has been heated to 
a dull red heat. 
When it is necessary to transport tissues some dis- 
tance they should be wrapped in bichloride cloths and 
sent to the point of destination as soon as possible. In 
warm weather they may be kept cool by surrounding 
the vessel which contains them with ice. 
Animals rarely show the same gross lesions as man 
when both suffer from the same infection. The cell 
changes are similar, and, also, so far as we can test them, 
the curative or immunizing effects of protective serums. 
