TEMPERATURE. 373 



plant all exhibit the same phenomenon of carbon in 

 combustion. 



A familiar example of the evolution of heat during 

 germination is furnished in the process of " malting" 

 the grain of barley. Growth is stimulated by 

 moisture, and a large number of seeds being collected 

 together it is easy to experience the increase of 

 temperature caused during the process. The chemical 

 change which the seeds undergo, the absorption of 

 oxygen, the state of slow combustion, the amount of 

 heat evolved, are all easily demonstrated. Thus we 

 ascertain that the change is a chemical one, the 

 starch of the seed by acquiring oxygen becomes 

 soluble and saccharine, this kind of decomposition 

 being accompanied by increase of temperature. The 

 process is essential to the growth of the plant. The 

 starch was insoluble, and therefore incapable of 

 nourishing the young embryo. By acquiring oxygen 

 it becomes soluble and growth proceeds, until checked 

 artificially by drying, and the starchy "barley" is 

 converted into the sugary " malt." That which is 

 here effected artificially is simply the ordinary course 

 of nature. 



From this process we learn that there is a chemical 

 change, accompanied by evolution of heat, to a 

 greater or less extent, in all seeds during germination. 

 So, also, at a subsequent period, namely, that of 

 flowering, certain chemical changes take place, which 



