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. 



