290 LABORATORY EXERCISES IN BACTERIOLOGY. 



autopsy be conducted, and from the metastatic abscesses let nutrient 

 tubes be inoculated and films prepared for microscopic examination. In 

 young animals note the occurrence of osteomyelitis. 



Exercise 82. Before the class let the instructor inoculate several 

 guinea-pigs with a bouillon culture of Bad. anthracis grown for three weeks 

 at a temperature of 42 C. Let the animals be exhibited to the class 

 during the period of reaction and after recovery. After recovery let them 

 be inoculated with a bouillon culture of the same organism grown at the 

 same temperature for two weeks; and after recovery from this let the 

 same operation be performed upon them with a similar culture grown 

 for but one week at the same elevated temperature. After several days 

 from the last inoculation let such an animal and one which has not been 

 subjected to the vaccines be inoculated with virulent anthrax to demon- 

 strate the acquirement of immunity by the influence of the vaccine. 



Exercise 83. Inject a guinea-pig of about two hundred and fifty grams 

 weight with one protective unit of diphtheria antitoxin (amount of anti- 

 toxin requisite to counteract one hundred fatal doses of the toxin of the 

 disease for an animal of such weight). Inoculate this and an unpro- 

 tected guinea-pig each with o.i cubic centimeter of a bouillon culture 

 of Mycobacterium diphtheria grown at body temperature for twenty-four 

 or forty-eight hours. Compare the results. From the pig dead from the 

 inoculation, at autopsy make smears from the site of inoculation and 

 from the interior organs and blood. Stain these and determine the 

 location of the germs. Make sections of the tissues and study the struc- 

 tural alterations evident about the site of the inoculation and in the 

 kidneys. 



