296 PHYSIOLOGY AND HEALTH. 



we have the same wants, and need the invigorating effects of 

 muscular action both winter and summer in fair weather 

 and in foul. Nor is there any sufficing objection to it, for 

 very few days of the winter are so cold that we cannot keep 

 ourselves comfortable by rapid walking, or other exertion , 

 and, indeed, the colder the weather the more dense is the 

 air, and the greater quantity of oxygen is received into the 

 lungs to sustain the internal fire. ( 444, p. 189.) Very few 

 days are so stormy as to prevent this exercise abroad, and on 

 such days it may be taken under cover of the house. 



684. This law for the health of the frame, and the neces- 

 sity of exercise abroad, is one and the same for both male 

 and female, for the rich and the poor. All can have a fuller 

 development of strength, and health, and life, by taking it 

 abroad ; and all must suffer the same depreciation of life if 

 they neglect it. There are none so favored in life as not to 

 need it, none so high as not to be benefited by it, and 

 very few so feeble as not to be able, in some degree or other, 

 to obtain it. 



685. Exercise should be frequent and regular. The sys- 

 tem wants this means of invigoration as regularly as it wants 

 new supplies of food for nutrition. Every day, therefore, 

 should have its own, and no day should have more. It is not 

 enough for health that we live inactively for several days, then 

 devote one day to action of the muscles. But many do so; 

 they have, in all, a sufficiency of exercise, but they take it 

 irregularly. A clergyman, of .very studious habits, devoted 

 Mondays to walking, or riding on horseback, and the rest of 

 the week to mental labor. While writing his sermons, he often 

 for three days scarcely left his room. He became dyspeptic. 

 Some teachers labor incessantly in their vocation for weeks 

 successively. They teach six hours daily in school, and read 

 and study the other waking hours out of it, with the intention 

 of devoting their vacation to excursions and labor, arid then, 

 they think, they shall get exercise enough for another term 

 of confinement. 



686 The industrious seamstress, earning her scanty pit 



