THE CHEMISTRY OF THE CKOP. 241 



the latter, the sheep eat the leaves in preference to the 

 stems, and a large portion is always wasted. It is a very 

 quick-growing crop, and, if properly managed, will yield a 

 large bulk of valuable keep, much relished by cows and 

 pigs, and well adapted for a cottager's cultivation, while, 

 when it ceases to be productive, the roots may be dug up 

 and treated for home consumption in the manner described 

 above. 



The analysis of its inorganic ingredients shows the large 

 proportion of potash that enters into its composition. 

 This is abstracted by its long, tap-shaped root from the 

 lower stratum of the subsoil, and being elaborated into its 

 structure the stems and leaves above the surface and 

 there consumed, its cultivation must tend very much to 

 enrich the agricultural soil with the valuable matters it 

 brings up from below. The organic composition of the 

 fresh root was determined by Dr. Anderson as follows : 



Compounds containing nitrogen, 172 



,, not containing nitrogen 16'09 



Ash (mineral matter), 1-31 



Water, 80'58 



100-00 



The results of his analysis of the ash are thus given : 



Potash, 42-60 55'27 



Lime, 6'09 7'90 



Magnesia, 3'15 4'09 



Phosphoric acid, 10'02 13'00 



Sulphuric acid, 4*80 6'23 



Carbonic acid, 11'40 



Peroxide of Iron, '81 T05 



Silica, -99 1-29 



Chloride of Potassium, 178 2*31 



Sodium, 6-83 8'86 



Sand, 1-12 



Charcoal, 9'90 



99-49 100-00 



In the second column of both the inorganic analyses, the 

 results were calculated with the omission of sand, charcoal, 

 and carbonic acid. 



