A. 1st—Because activity increases the warmth of the body, by fanning the combustion of the blood: and
2ndly—The strong food we eat creates a desire for muscular exertion.
Q. Why are the Esquimeaux so passionately fond of train oil and whale blubber?
A. Oil and blubber contain a very large amount of hydrogen, which is exceedingly combustible; and as these people live in climates of intense cold, the heat of their bodies is increased by the greasy nature of their food.
Q. Why do we feel a dislike to strong meat and greasy foods in very hot weather?
A. Strong meat and grease contain so much hydrogen, that they would make us intensely hot; and therefore we refuse them in hot weather.
Q. Why do we like fruits and vegetables so very much in hot weather?
A. Fruits and vegetables contain less carbon than meat, and therefore produce less blood: instead of blood, they combine into water as they are digested, and keep the body cool.
Q. Why do people say that fruits and vegetables cool the blood?