CHAPTER XV. 



PHYSICAL CAUSES OP MENTAL DIFFERENCE AND DISORDER. 



II. Pathological. 



THERE is no reason to doubt that lowered vitality in all its 

 degrees and however brought about is as fertile and as 

 inevitable a cause of mental disorder in other animals as in 

 man. The causes, moreover, of general feebleness of health 

 are the same in kind as those which operate in man, includ- 

 ing, as they do, 



1. All sources of physical exhaustion or fatigue, such as 

 that resulting from 



a. Excessive work. 



"b. Serious drain or discharge from the system of 

 important fluids, such as the blood. 



c. The injudicious, debilitating treatment of as- 



thenic maladies. 



d. Protracted weakening diseases. 



2. Privation of food or drink, or the use of aliment that 

 is innutritions. 



3. Undue exposure to the weather. 



4. Overcrowding amidst foul air. 



5. Disordered or deficient relaxation, rest, or sleep. 



6. Personal uncleanliness of skin and its appendages, 

 arising from neglect of bathing, or from deficiency of water 

 for ablution. 



7. All kinds of artificial and unhealthy habits, especially 

 those which involve defective work and exercise. 



Some of these causes are more provocative than others of 

 nervous irritability, and of ill-health of a nervous type in 

 which type of disordered health, morbid mental conditions are 



