172 HOW CROPS GROW. 



acteristic ingredient, existing there in connection with a 

 large amount of potash (32%) and considerable magne- 

 sia. Chlorine acquires its maximum (11.7%) in the mid- 

 dle stem, but in the kernel is present in small quantity, 

 while sulphuric acid is totally wanting in the lower stem, 

 and most abundant in the upper leaves. 



Again, the unequal distribution of the ingredients of 

 the ash is exhibited in the leaves of the sugar-beet, which 

 have been investigated by Bretschneider ( Hoff. Jahresbe- 

 richt, 4, 89). This experimenter divided the leaves of 6 

 sugar-beets into 5 series or circles, proceeding from the 

 outer and older leaves inward. He examined each series 

 separately with the following results : 



I. II. III. IV. V. 



Potash 18.7 25.9 32.8 37.4 50.3 



Soda 15.2 14.4 15.8 15.0 11.1 



Chloride of Sodium.... 5.8 6.4 5.8 6.0 6.5 



Lime 24.2 19.2 18.2 15.8 4.7 



Magnesia 24.5 22.3 13.0 8.9 6.7 



Oxide of Iron 1.4 0.5 0.6 0.6 0.5 



Phosphoric acid 3.3 4;8 5.8 8.4 12.7 



Sulphuric acid 5.4 5.6 5.6 5.2 5.9 



Silica 1.5 0.8 2.7 2.1 1.5 



From these data we perceive that in the ash of the leaves 

 of the sugar-beet, potash and phosphoric acid regularly 

 and rapidly increase in relation to the other ingredients 

 from without inward, while lime and magnesia as rapidly 

 diminish in the same direction. The per cent of the other 

 ingredients, viz., soda, chlorine, oxide of iron, sulphuric 

 acid, and silica, remains nearly invariable throughout. 



Another illustration is furnished by the following anal- 

 yes of the ashes of the various parts of the horse-chestnut 

 tree made by Wolff (Ackerbau, 2. Auf., 134): 



Bart. Wood. Leaf-stems. Leaves. Floieer-itemt. Calyx. 



Potash 12.1 25.7 46.2 27.9 63.6 61.7 



Lime 76.8 42.9 21.7 29.3 9.3 12.3 



Manncsia 1.7 5.0 3.0 2.6 1.3 5.9 



Sulphuric acid trace trace 3.8 9.1 3.5 trace 



Phosphoric acid 6.0 19.2 14.8 22.4 17.1 16.6 



Silic-a 1.1 2.6 1.0 4.9 0.7 1.7 



Chlorine 2.8 r>.i 12.2 5.1 4.7 2.4 



