240 THE DIGESTIVE ORGANS. 



Kind of Food Kequired If we eat only those articles 

 most easily digested the digestive powers will be weakened for 

 want of exercise; while if we pursue the opposite course they will 

 be exhausted by overwork. The kind and amount of food should 

 therefore be adapted to the maintenance of the digestive 

 powers when in health and to their gradual invigoration when 

 debilitated. However, the most easily digested food is not always 

 best for a person recovering from sickness, because if it passes too 

 readily through the digestive process it may bring on a relapse into 

 the original disease. Thus water-gruel is often better for a conva- 

 lescent than beef -tea and fish, though the latter are more easily 

 digested. 



Animal or Vegetable Food It is not yet well settled 

 which of these is better adapted to nourish man. The people of the 

 torrid zone subsist chiefly on vegetables, and a large proportion of 

 these are fruits; while those of the frigid zone live principally on 

 fish and flesh. There is little doubt that in this both obey the con- 

 dition of health peculiar to either climate; though in the latter very 

 little choice is possible. It would seem to follow then that a mixed 

 diet of animal and vegetable food, the proportion of either varying 

 with the latitude, is best for the inhabitants of more temperate 

 zones. The form and arrangement of the human teeth, as well as 

 the structure of the stomach and intestines, would perhaps lead us 

 to conclude that a mixture of animal and vegetable food is on the 

 whole best for all, wherever they may happen to live. 



Adaptation of Food The distensible character of the 

 stomach and alimentary canal should determine this. "While the 

 human stomach will be full if it contain but a gill, it may be so 

 distended as to hold a quart, or even more. The intestines also are 

 extremely distensible. Now, if this distensible quality is unused, 

 as it must be if only nutritious food is used, they become at last 

 incapable and diseased. The digestive organs absolutely require 

 the stimulus of distension and friction caused by the passage 

 through them of a considerable quantity of wholly innutritions 

 material. This is the reason unbolted flours are so generally pre- 

 scribed for dyspeptics; and, as it is quite evident that the natural 

 tendency of sedentary habits is in this direction, enfeebling the 

 appetite and the whole digestive apparatus, persons so employed 

 ought to be particularly careful on this point. 



Any one in whom there appears a tendency to either diarrhea 

 or constipation may generally so apply this principle as to check 

 the tendency and be restored to health without other aid. In diar- 

 rhea the food should contain a very small proportion of waste or 

 innutritions matter, while in constipation the proportion of waste 

 should be as large as practicable. 



Season and Climate These should always be considered 

 in the selection of food. In cold weather, food of a highly stimu- 

 lating character may be used almost with impunity by persons to 



