LESSON FORTY-TWO 
MEANING OF DISEASE 
1. Sickness—An animal is in a healthy state when 
each organ or part forms its natural functions. Any 
departure from a normal con- 
dition of health is disease. 
Thus any disturbance of the 
brain or spinal cord is immedi- 
ately manifested in the action 
of the animal; frequently also 
a disturbance elsewhere may 
later affect the mental system. 
Disease may result from an ex- 
ternal cause, as from a wound; from food causing 
poison or derangement of the digestive system; from 
water introducing impurities ; from parasites and bacteria 
which disturb normal functions, disorganize the tissue, 
or produce toxines; or from other abnormal conditions. 
2. Disease both general and local.—A disease may lead 
to disturbance throughout the entire body. For instance, 
in case pus accumulates at some point, it may get into 
the blood and reach other parts of the body in time, affect- 
ing them also. Diseases with which fever is associated 
are general in nature. The nerve centers are influenced, 
body htat is increased, the body gets weak. Disease 
poisons are fundamentally the cause of fever. 
When the temperature of the body, as a result of fever, rises to 
an extreme height, certain life principies are changed and death 
immediately follows. A temperature of 106 or 107 degrees is very 
high, and, therefore, very dangerous. In treating disease the tem- 
perature is watched, that the course of the fever may be followed. 
449 
Bybee ae! pala, 
WuHat Is THE TROUBLE? 
