604 Introduction to the Study of Science 



27. What use is made of antitoxins? 28. What is an antitoxin? 

 29. What sort of protection does it give ? 



30. In what ways may disease germs be controlled or destroyed? 



31. (a) What is a disease carrier? (6) Why is such an unsuspected 

 carrier more dangerous than a patient suffering with the disease? 



32. What precautions should those afflicted with a disease take to 

 protect others? 33. What conditions necessitate public control of 

 disease? 34. What means should one in good health take to protect 

 oneself from disease? 35. Mention precautions which should be 

 taken in the market, in dairies and restaurants, and in the home? 

 36. What are the advantages and disadvantages of isolation of the 

 patient and persons exposed to infection? 37. Mention material 

 means by which disease may be communicated. 38. In what ways 

 does cleanliness help us to keep well? 39. When is disinfection 

 necessary? 40. (a) What is concurrent disinfection? (6) What 

 are its advantages? 41. (a) When is subsequent disinfection indis- 

 pensable? (6) What are the most effective means? 42. Mention 

 several disinfectants, their advantages, and disadvantages. 



43. State Ehrlich's theory of immunity, explaining the function 

 of the chemical side chains in normal and abnormal conditions ; the 

 formation of antitoxins ; the action of the antitoxin. 44. Explain 

 why tetanus is difficult to cure. 45. Explain how the antitoxin 

 for diphtheria acts, according to the chemical theory. 



46. What is the theory of Metchnikoff ? 47. How does this theory 

 apply in the case of malaria? 48. How may immunity be acquired 

 in accordance with Metchnikoff 's theory? 49. Show that both 

 theories may be true and necessary. 50. What use is made of the 

 knowledge of the chemical nature of antitoxins produced in the body 

 when it is resisting disease? 51. For what kind of bacterial diseases 

 are artificial antitoxins prepared and used? 



III. VACCINES AND ANTITOXINS 



295. Vaccines. In the eighteenth century Lady Mary 

 Montagu introduced into western Europe the practice of 

 inoculation for smallpox, which had long been common in 

 Turkey and many sections of the Orient. As generally prac- 

 ticed, the healthy person was inoculated through an open cut 

 in the skin with the virus taken from the smallpox sore of a 

 patient with a mild form of the disease. Although this was 



