PROBLEM 3. Recent Discoveries Change Our Ideas About Disease 341 



Fig. 303 A college bacteriology laboratory. Here students learji iinicb vwre about bac- 

 teria than can be learned in a high school course. Which parts of their equipment do 

 you recognize? (university of Massachusetts) 



\\hich cause intestinal diseases, such as 

 tvphoid and dysentery. Sometimes it did, 

 sometimes it did not, bring about im- 

 provement in the patient. D'Herelle 

 hoped that bacteriophage might be 

 spread from person to person in certain 

 epidemics to kill the bacteria. Animal ex- 

 periments, however, showed that the 

 bacteriophage was of no help in prevent- 

 ing the spread of disease. 



As with virus, there is still dispute 

 about whether bacteriophage is a living 

 organism or a lifeless protein. Whatever 

 the answer may be, at present it looks as 

 though bacteriophage will not be as im- 



portant in conquering disease as was 

 once hoped by a few scientists. 



The future. No one can predict what 

 developments will occur in the near fu- 

 ture in the prevention and the cure of in- 

 fectious diseases. But there are so many 

 promising possibilities for the produc- 

 tion of new vaccines and of satisfactory 

 antibodies, of chemical drugs and of 

 antibiotics that we can hope much pain 

 and suffering will be spared us. This is 

 a great and growing field for scientists; 

 it is a field of great service to mankind as 

 well as a field of exciting scientific war- 

 fare against deadly germs. 



2. 



Questions 



What is now known about pneumonia and its cause? Give an ex- 

 ample of how germs change in virulence. 



Describe two chemical experiments which show how important 

 chemistry is to the bacteriologist. 



