30 ENVIRONMENT OF PLANTS AND ANIMALS 



I^rohletn (i : To make a graph to show how much fluid I take 

 into my body in a day. 



Method and Observations. — Make a careful estimate of the 

 amount of water drunk by glasses or cups and note hours when 

 you take it. Note also milk, coffee, tea, soda, etc., taken. Make 

 a graph to show when and how much fluid passes into the body in 

 24 hours. 



Is this graph a continuous curve? Explain. 



Note. — Ability to make and to understand graphs is something that every well- 

 educated girl and boy should acquire. The above exercises are suggested as easy 

 data for making two different graphs, each of which will have a different ap- 

 pearance. Teachers are expected to give the class data from which other graphs 

 may be constructed. 



Problem 7 : May environment influence public health ? 



Method and Observations. — Study the following table. Look 

 up the location of each of the countries and cities. Find out all 

 you can about their climate, housing conditions, location and con- 

 dition of water supply, etc. 



Death Rate per 10,000 Population, Pneumonia and Bronchitis, 



Five-Year Period 1896-1900 



England and Wales 22.70 



Scotland 27.40 



Stockhohn 26.70 



London 31.20 



Berlin 16.10 



Vienna 39.70 



Christiania 21.30 



Boston 30.60 



Chicago 24.20 



Philadelphia 25.10 



New York city 36.60 



Might any factors, such as climate, slums, overcrowding, etc., 

 have an effect upon the death rate? 



Conclusion. — What factors may influence the death rate? 



