Of course, not all deaths from a given disease could be prevented even with the best known means. Infant diseases constitute one class which is considered most hopeful of betterment through a pure milk supply and better hygiene; and yet many authorities believe that not more than half the deaths could be prevented owing to the large part played by weather conditions, feeble constitutions, and other unchangeable conditions.
Preventable diseases may be divided into six classes:
(1) Diseases caused by lack of proper hygiene.
(2) Diseases caused by bad habits.
(3) Contagious diseases.
(4) Diseases caused by insects.
(5) Accidents, wounds, or operations and their resulting diseases.
(6) Diseases remedied by slight means.
We will treat each of these in turn.
(1) By proper hygiene is meant the proper treatment of the body as to breathing, eating, drinking, sleeping, bathing and rest. This treatment includes plenty of fresh air, both day and night, keeping outdoors as much as possible, and in well-aired houses the rest of the time. Vigorous but not violent exercise, brisk walking, regular physical exercise, such as is practised in gymnasiums, will go far toward keeping the body in good condition.