CONTAGIOUS DISEASES 



391 



LABORATORY EXERCISE 33 



Purpose. To compare the death rates for various diseases. 

 . Materials. Figures 150 and 155. 



Directions, i. In figure 155 notice which three diseases cause 

 the greatest number of deaths. Which five the least. 



2. Make a table like the following in your notebook. 



Fill in the figures for the first three columns for each disease for 

 1916, counting the population of the United States as 100,000,000. 

 Put first the disease with the highest death rate and arrange the 

 rest in order. 



3. Beginning with diseases having the lowest death rate, add 

 together the number of people killed till you get a total equal to 

 the number killed by tuberculosis alone. How many and what 

 diseases does it take to do this ? 



4. For which diseases has the death rate been decreasing ? For 

 which increasing ? Compare 1916 with 1900 and work out for each 

 disease the per cent of increase or decrease. Put the figures in the 

 fourth column of the table above. 



Are the diseases that are decreasing contagious or organic 

 diseases ? Which are those that are decreasing ? See if you can 

 find out, either by using books or by asking a physician, why there 

 have been these changes. 



5. Study figure 150 to notice the effect of vaccination on the 

 death rate from smallpox. What does the figure show (a) for 

 Prussia, (b) for Holland, (c) for Austria? 



6. In Prussia what was the average annual death rate for the 

 six years before vaccination was made compulsory? What was 

 it 'for the six years after ? The population of Prussia for 1880 was 

 27,000,000. Compute the number of lives saved in this country 



