other times.

_Take plenty of exercise._

The more you can exercise in the open air the better. And if you take
exercise you will find it possible to be out of doors on very cold days.
If you are not strong on your feet, perhaps you are strong in the
muscles for rowing. If you cannot row, perhaps you can ride. If you
cannot ride, perhaps you can drive. If you cannot drive, perhaps you can
exercise in the gymnasium. If you cannot do any of these things, do what
you can. Walk from your door to the street and back again. Do the same
thing over in fifteen minutes, and unless you are a miserable _bona
fide_ invalid your muscles will soon become more useful. Doing errands,
and going about to people who need you, will give you valuable exercise
for which you take no thought.

But some of you are too busy to exercise many hours a day in the open
air, and so you ought to be. The next best thing for you is housework.
Perhaps you do not like that because you see it under the wrong angle of
vision. Whether you like it or not, it is within reach of most of you,
and would do you good.

But suppose your books and your sewing are necessary and keep you busy
all day. Then you are to remember to change your position often. At the
end of every hour, when you open the window, take a few deep breaths,
stretch your arms and legs and fingers, and you will be better able to
go on with your task.

_Eat such food as you can thoroughly digest._

There are persons who are always troubled as to what they shall eat, and
who, with all their care, are always ailing. I do not want you to think
about your food so much that you can digest nothing, but I believe that
a very little observation will teach you what is good for you
individually. If you have a dizzy head, or rising of food, or a bad
breath, or uneasiness of the bowels, you may be pretty sure that you
have eaten something that disagrees with you, and by a little
watchfulness you may discover what it is and avoid it.

Food that you can digest very well when you are fresh may be much too
heavy for you when you are tired. And if you are thinking intently while
you eat, the blood is drawn from the stomach where it should be to the
brain where it should not be. Few people can digest vegetables not
thoroughly cooked, or fruit not thoroughly ripe. I think the study of
Physiology is of more practical hygienic value in teaching the absolute
necessity of using food that can be readily assimilate