EVILS OF DEFICIENT EXERCISE. 125 



are habitually subject to castiveness and its attend- 

 ant evils. The reason is the same. In the natural 

 state, the contents of the bowels are propelled partly 

 by the successive contractions of the muscles which 

 form the walls of the belly, and separate that cavity 

 from the chest ; and partly by the contraction of the 

 muscular fibres, which constitute an important part 

 of the structure of the intestinal canal. If, however, 

 exercise be refrained from, and the same position be 

 preserved for many hours a day, as in sitting at a 

 desk, the bowels are necessarily deprived of one im- 

 portant source of power; and thus weakened, they 

 are unable to act upon and propel their contents 

 with the same regularity as when assisted by exer- 

 cise. A slowness of action ensues, which no course 

 of medicine, and scarcely any modification of diet, 

 can overcome, so long as sedentary habits are in- 

 dulged in ; but which also may often be relieved by 

 daily pressing over the region of the abdomen with 

 a kind of kneading motion, imitating, though feebly, 

 the effects of muscular action. Females suffer much 

 from intestinal debility caused by sedentary habits. 



The evils arising from deficiency of exercise to all 

 the functions of the mind and body will now be 

 equally evident and intelligible, for they are the con- 

 verse of what we have seen to be the advantages of 

 adequate exercise. The circulation, from want of 

 stimulus, becomes languid, especially in the extreme 

 vessels; the feebleness of action occasions little 

 waste of materials; the appetite and digestion con- 

 sequently become weak ; respiration heavy and im- 

 perfect ; and the blood so ill-conditioned, that, when 

 distributed through the body, it proves inadequate to 

 communicate the stimulus requisite for healthy and 

 vigorous action. The concatenation of causes and 

 consequences thus exhibited cannot fail, when the 

 principle connecting them is perceived, to interest 

 and instruct every thinking mind. 



The time at which exercise ought to be taken is 

 L2 



