MANUAL OF NATURE STUDY. 
61 
Then require the school to take vigorous exercise 
of some sort, and take records again. 
Why does the circulation increase in rapidity ? 
Why the increase in breathing ? 
To supply this waste requires food. Foods are 
of four kinds, viz.: The albuminoids, starch and 
sugar foods, fats, and mineral foods. 
Bread, milk,beans, peas, fish, lean meat and eggs 
are regarded as strength-producing foods. These 
are called albuminoids, because they contain 
albumen, a substance closely resembling the white 
of an egg. 
The starches are found in bread, oatmeal, pota¬ 
toes, beans, corn and wheat in any form, fruits, 
rice. 
The heat-producing foods are fats from animals, 
and oils obtained from nuts. By eating nuts, but¬ 
ter on our bread, fat pork or beef, we keep up the 
heat of the body. In cold countries, like Klon¬ 
dike, it is necessary to eat a great deal of fat. The 
natives eat the fat of walruses and seals. 
What would the natives of Cuba or the Philip¬ 
pines eat ? Would they have any use for walruses 
or whale blubber ? Why ? 
All meats are valuable as food. Pork is hardest 
to digest. It also contains a large amount of fat. 
Then would it be good food for a hot or cold 
