CHAPTER VIII 

 The Meaning of Disease 



Any departure from a normal condition is dis- 

 ease. The body, composed of different organs and 

 parts, is in a healthy state when each of these 

 performs its natural functions. Thus the normal 

 mind is concerned with normal mental acts; any 

 disturbances of the brain or spinal cords is imme- 

 diately manifested in the action of the animal; 

 likewise frequently a disturbance elsewhere may 

 later have its effect on the mental system. 



Disease may result from some external cause 

 like from a wound, from food causing poison or 

 derangement of the digestive system, from water 

 introducing impurities, from parasites that disturb 

 normal functions, disorganize tissue or produce 

 toxines, or from other abnormal conditions — all of 

 which interfere with the normal functions of one 

 or more organs, regions, or parts. 



In most cases the disturbances are readily recog- 

 nized. Swellings, bruises and wounds are located 

 at a glance. When blood passes from nose, ears 

 or intestines, a key to the trouble is at hand. 

 Coughs have their story. And vomiting, diarrhoea, 

 convulsions, spasms, abnormal breathing or tem- 

 perature each indicates at what points an abnormal 

 condition is evident. 



Disease, Both General and Local. — Some diseases 

 lead to disturbance throughout the entire body. 

 For instance, pus may accumulate at some point 

 from which it finds its way into the blood, in the 

 end reaching to other parts of the body that in time 

 also become affected. 



