58 THE PRINCIPLES OF AGRICULTURE. 



1. The Absorption of Moisture. It is evident that 

 the nutritive substances contained in the seed cannot 

 pass into the plant and support growth while in a dry 

 state. The seed must be saturated with moisture, so that 

 there may be a medium through which these substances 

 may pass to the point in the growing plant where they 

 are needed. 



2. A Change in the Nutritive Substances. The sup- 

 plies of food stored in the seed are not generally in a 

 suitable form to support the plant, but must first be 

 changed. They are dissolved in the moisture, and con- 

 verted by chemical processes into the proper forms. An 

 instance of this is the conversion of starch into sugar. 

 The formula for starch is C 6 Hi 5 , and for the glucose 

 sugar obtained from it, C 6 Hi 2 6 . The latter is obtained 

 from the former by the addition of oxygen and hydrogen. 



In the process of malting barley and other kinds of 

 grain, the aim is to obtain these same chemical changes. 

 The grain is soaked and allowed to sprout until the 

 starch and other substances are converted into sugar, 

 dextrine, etc. The process is then stopped by drying, 

 and the new substances are extracted from the grain to 

 form malt. 



3. The Production of Heat. The changes above re- 

 ferred to are largely due to oxidation, or the combina- 

 tion of oxygen with the substances of the seed. This, 

 as in other instances of oxidation, produces heat. 



If a large number of seeds are heaped together, as in 

 manufacturing malt, the mass becomes very warm, so 

 much so that care is required to prevent the grain from 

 spoiling. This heat, developed in the sprouting seed, is 

 of some service at times when the temperature outside 

 is too low. 



