HEAT-GIVING FOODS. 
143 
7 . “If you tie a piece of grated yam or cassava 
in a muslin bag, and then wash it well in a glass of 
water, you will find that the water becomes milky 
in appearance. This is because of the starch which 
washes out of the yam, and it will settle to the 
bottom in a fine powder if you leave the water at 
rest for a time.” 
8. “I shall try to find the starch in some of the 
foods in that way,” said May. 
“ Do so, by all means. If we had a microscope 
Section of Wheat Grain— highly magnified. To the right the granules of 
wheat starch are shown more highly magnified. 
we should be able to see that the starch powder is 
made up of little grains, marked with rings; so that 
starches from different plants are known by their 
shapes and markings. 
9. “ As for sugar, it is present in the sugar-cane, 
the beet-root, and the sugar-maple, in many fruits, 
and in milk. 
“ Neither starch nor sugar can form flesh and 
muscle. Instead, they slowly ‘ burn’, and in doing 
so give out heat. This is also true of fats and oils 
