ACTIVE IMMUNIZATION OF ANIMALS 891 



2. The working table should be set in order after each day's work; 

 pipets and soiled glassware should be properly disposed of, instruments 

 thoroughly cleansed, and the table wiped off with 1 per cent, formalin 

 solution. It should be impressed upon the student that good and ac- 

 curate work is seldom done amid disorderly and dirty surroundings. 



3. The student must never sacrifice accuracy for speed; painstaking 

 and accurate work is always to be desired; speed is gained only with 

 practice. 



Records. Each worker should record in writing in a suitable note- 

 book his observations of the various tests and experiments. Not infre- 

 quently unexpected results are obtained, and it is important to under- 

 stand and explain these as correctly as possible. Note-books should be 

 subject to frequent inspection; it is not necessary to write out a descrip- 

 tion of the technic, but the results of the experiment and answers to the 

 questions should be set forth clearly and with sufficient detail. 



Animal Experiments and Autopsies. In all experiments calling for 

 operative procedure an anesthetic is to be used in order that unnecessary 

 pain be avoided. Ordinarily, ether is to be employed, or in rabbits the 

 rectal injection of 0.5 to 1 gram of chloral hydrate dissolved in 5 to 10 c.c. 

 of water. Autopsies are to be carefully conducted, and the lesions 

 described in writing. After autopsy the table is to be scrubbed and 

 cleansed with a solution of formalin, and the carcass disposed of by in- 

 cineration or placing in a solution of formalin until removed and other- 

 wise disposed of. 



EXERCISE J. ACTIVE IMMUNIZATION OF ANIMALS 



EXPERIMENT 1. PRODUCTION OF AGGLUTININS, BACTERIOLYSINS, AND 

 OPSONINS 



1. Secure a culture of Bacillus typhosus, an old laboratory culture of cholera 

 bacilli, and a culture of Staphylococcus aureus. 



2. Proceed to immunize two rabbits with each culture by intravenous injections 

 according to the technic described on page 68. 



3. One week after the last injection the animals are to be bled and the serums 

 secured after the first method described on page 41. 



(a) Define the meaning of antigen. 



(b) What are antibodies? 



(c) What is meant by active immunization? 



(d) What precautions should be observed in handling these antigens? 



(e) What precautions are to be observed in giving intravenous injec- 

 tions? 



