226 MICROBES AND HEALTH. 



important properties in common, and contain two im- 

 portant substances in common; i. e., sugar and starch. 

 Sugar is chiefly of vegetable origin, the animal varieties 

 being honey and the sugar found in milk. Sugar and 

 starch are vegetable products, and under favorable cir- 

 cumstances unite readily with the oxygen in the blood 

 and produce water, carbonic acid and heat. 



The three vital processes of life in both plants and 

 animals are digestion, circulation and respiration. 

 Both receive their nourishment from the air and soil. 

 Chief among the substances are wheat, corn, rye, oats, 

 barley, rice, etc. Collectively these are called cereals, 

 and are said to contain all the elements necessary to 

 maintain human life. There is said to be no record 

 that takes us back or beyond the cultivation of wheat. 

 It has been found in the lake dwellings of the ancient 

 Swiss, and many believe it has existed since man has 

 existed. 



It is estimated that two-thirds of our food is starch. 

 Uncooked starch is indigestible. Unripe fruit contains 

 starch, hence the danger of eating it uncooked. The 

 starch is converted into sugar during the process of 

 the fruit's ripening. Some fruits contain sugar in con- 

 siderable quantities, giving them a sweet taste. This 

 is grape or starch sugar, and it is only one-half as sweet 

 as cane or granulated sugar. 



Much has been said and written concerning the food 

 products what we should and should not eat. But 

 when it comes to the question of food and drink, we 

 are continually making mistakes. As evidence, we have 



