16 THE GBAPE. 



Boussingault * gives the amount of the incombus- 

 tible components of the grape-juice in Alsace in the 

 following manner : 



Potash 0-842 



Lime 0'092 



Magnesia (V172 



Sulphuric Acid 0'096 



Chlorine traces 



Carbonic Acid 0'250 



Phosphoric Acid O412 



Silicic Acid 0'006 



He finds that the vine in these districts absorbs in 

 the course of the year the following quantities per 

 hectare (about 2 J acres of cultivated land) : 



Potash 16-42 



Soda 0-15 



Lime 12'49 



Magnesia 3'24 



Phosphoric Acid 7'23 



Sulphuric Acid T93 



In the same districts the ground is exhausted in 

 the following proportions per hectare : 



Alkali. Phosphoric Acid. 



Potatoes 63 14 



Mangel Wurzel 90 12 



Wheat with straw 27 ;9 



According to this, the assertion that the vine 

 requires more alkali than other plants, on account of 

 the grapes alone, is erroneous, nor can any probable 

 reason be alleged for maintaining that the removal 

 of the grapes alone, while the constituents of ash 



* Ann. de Ch. et de Phys. 3 Serie, torn. xxx. p. 369. 



