USES OF STARCH 99 



"It is chiefly by the varying size of their micro- 

 scopic grains that the starches of different kinds 

 are distinguished from one another. In substance 

 and structure they are all alike. Placed in warm 

 water, their grains swell, burst, expand their leaflets, 

 and the starch, from whatever source, is changed 

 into a glutinous jelly. 



"Starch is the food supply of plant-life. Wher- 

 ever we find buds that are intended to develop by 

 themselves, wherever we find germs, there also we 

 shall find a supply of starch serving as a sort of 

 food reserve. Hence this peculiar provision is met 

 with in tubers, bulbs, bulblets, seeds, and fleshy roots. 

 Now when these buds and germs develop, the starch 

 becomes, in the process of vegetation, a kind of sugar 

 which, being soluble in water, can be sent to all parts 

 of the young plant and serve it for food. 



"By certain artificial devices this same change 

 of starch into sugar can be brought about. The 

 simplest of these devices is the application of heat, 

 which always enters into the preparation of farina- 

 ceous food. Let us take a few examples. A raw 

 potato is uneatable. Boiled in water or roasted in 

 the ashes, it is excellent. What has happened, then? 

 Heat has converted a part of the starch into sugar, 

 and the tuber has become a sugary farinaceous paste. 

 The same can be said of the chestnut. Raw, it is no 

 great delicacy, although at a pinch it can be eaten; 

 cooked, it is worthy of all the praise we can give it. 

 I appeal to you to back me up in this assertion. 

 Here, then, we have another transformation of starch 



