XXIX. HEALTH AND DISEASE— A CHAPTER ON CIVIC 



BIOLOGY 



Problem. LVI. A study of -personal and civic hygiene. {Lctbo- 

 ratory Manual, Prdb. L VI.) 



Health and Disease. — In previous chapters we have consid- 

 ered the body as a machine more delicate in its organization than 

 the best-built mechanism made by man. In a state of health this 

 human machine is in a good condition; disease is a condition in 

 which some part of the body is out of order, thus interfering with 

 the smooth running of the mechanism. 



Personal Hygiene. — It is the purpose of the study of hygiene 

 to show us how to live so as to keep the body in a healthy state. 

 Hygiene not only prescribes certain laws for the care of the various 

 parts of the body, — skin, teeth, the food tube or the sense organs, 

 — but it also shows us how to avoid disease. The foundation of 

 health later in life is laid down at the time we are in school; for 

 that reason, if for no other, a knowledge of the laws of hygienic 

 living are necessary for all school children. Unlike the lower 

 animals, we can change or modify our immediate surroundings so 

 as to make them better and more hygienic places to live in. Hy- 

 gienic Hving in our home must go hand in hand with sanitary 

 conditions around us. It is the purpose of this chapter to show 

 how we do our share to cooperate with those in charge of the 

 public health in our towns and cities. 



Some Methods of Prevention of Disease. — ■ The proverb " An 

 ounce of prevention is worth a pound of cure " has much truth in 

 it. Disease is largely preventable. Fresh air, the needed amount 

 of sleep, moderate exercise, and pure food and water are essentials 

 in hygienic living and in escape from disease. 



Pure Air Needed. — • What do we mean by fresh air, and why do 

 we need it? We have already seen that oxidation takes place 

 within the body, and that air containing as little as 2 parts of 

 respired carbon dioxide to 10,000 parts of air is bad for breathing. 



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