THEORY OF DISEASE. 255 



childhood or in old age. A cause of disease may, 

 when it is added to the cause of waste in old age, 

 produce death (annihilate all resistance on the part 

 of the vital force) ; while in the adult state it may 

 produce only a disproportion between supply and 

 waste ; and in infancy, only an equilibrium between 

 supply and waste (the abstract state of health). 



A cause of disease which strengthens the causes 

 of supply, either directly, or indirectly by weakening 

 the action of the causes of waste, destroys, in the 

 child and in the adult, the relative normal state of 

 health ; while in old age it merely brings the waste 

 and supply into equilibrium. 



A child, lightly clothed, can bear cooling by a low 

 external temperature without injury to health ; the 

 force available for mechanical purposes and the tem- 

 perature of its body increase with the change of 

 matter which follows the cooling; while a high 

 temperature, which impedes the change of matter, 

 is followed by disease. 



On the other hand, we see, in hospitals and chari- 

 table institutions (in Brussels, for example) in which 

 old people spend the last years of life, when the 

 temperature of the dormitory, in winter, sinks 2 

 or 3 degrees below the usual point, that by this 

 slight degree of cooling the death of the oldest and 

 weakest, males as well as females, is brought about. 

 They are found lying tranquilly in bed, without the 

 slightest symptoms of disease, or of the usual recog- 

 nizable causes of death. 



