PROBLEM 2. How We Cmi Cofupier Some Diseases 335 



3. State Koch's four postulates. 



4. With what problems did Pasteur concern himself in his early years? 

 What is meant by fermentation? How did this work lead him to the 

 belief in the germ theory of disease? 



5. To what important problem did Pasteur turn once the germ theory 

 was established? Explain how chickens were made immune to chicken 

 cholera. What must be done to germs if they are to be used for 

 giving active immunity? How were the germs treated in each of the 

 two diseases, chicken cholera and anthrax? 



6. What is probably the cause of rabies? How does it enter? Where 

 does it seem to settle in the body? Describe how the material used 

 for inoculation is prepared. Why can it prevent the disease if used 

 to inoculate? 



7. What is one reason why smallpox was so widespread before 1800? 

 What material did Jenner use to prevent smallpox and why did he 

 call the process vaccination? 



8. To what extent has smallpox been stamped out in the United States 

 and Europe? Why? What precautions are taken in the preparation 

 and use of vaccine to make it safe? 



9. Why is Pasteur sometimes said to have saved more lives than Napoleon 

 took? 



10. How do typhoid germs enter and leave the body? Why is it impor- 

 tant that we all know these facts? State exactly what effect inoculation 

 against typhoid has had. 



1 1 . Against which three children's diseases have doctors recently per- 

 fected a.method of giving active immunity? 



12. How does von Behring's inoculation against diphtheria differ radically 

 from the various vaccinations described above? Why is the horse 

 said to have active immunity, the person passive immunity? Did von 

 Behring give antitoxin mostly as a preventive or as a cure? Why is it 

 better for the one than the other? In what year does the chart show 

 a very great and a permanent drop in the death rate from diphtheria? 

 Explain. 



13. Give all the steps in the preparation of diphtheria antitoxin and give 

 the reason for each step. 



14. Why did doctors look for an active immunization against diphtheria? 

 Who discovered this? How was it originally given? How has the 

 method been changed recently? 



15. How can a physician determine whether you are susceptible or im- 

 mune to diphtheria? Of what advantage is this? 



i 6. In what important respect does the tetanus germ dift'er from all other 

 common germs? Why is this important to us? How does the tetanus 

 germ enter the body? Explain why tetanus germs are likely to be 

 found in the soil. How are tetanus toxoid and tetanus antitoxin used? 



17. What is immune serum? For which diseases is it used? Does it give 

 •active or passive immunity? 



