224 



DR. DAT7EENY ON THE ROTATION OF CROPS, ETC. 



Permanent Crop of Potatoes. 



Tubers, 1000 grains yielded 



100 grains of this ash consisted of — 



Sand and charcoal, extraneous 

 Peroxide of iron, extraneous . 



■ 127 of ash. 



724-0 of water. 



263*3 solid organic matter. 



1000-0 



14-40 

 3-30 



1770 



Silica 1*57 



Phosphoric acid ........ 10*68 



Sulphuric acid 3-74 



Carbonic acid 10-68 



Chloride of sodium ....... 2*79 



Chloride of potassium ...... 3*09 



Potass 37-47 



Soda 0-00 



Magnesia 7*00 



Lime 364 



Real ingredients . . . 

 Shifting Crop of Potatoes. 



Of the tubers, 1000 grains yielded 



98-24 

 1770 



80*54 



10*8 of ash. 

 719*0 of water. 

 .270*2 solid organic matter. 



10000 



100 grains of this ash consisted of — 



Sand and charcoal * . . 2*16 



Peroxide of iron 5*15 



7*31 



Silica 6*60 



Phosphoric acid 15*13 



Sulphuric acid 2*21 



Carbonic acid 1 r03 



Chloride of sodium 1-87 



Chloride of potassium 0-00 



Potass 46- 12 



Soda 0*78 



Magnesia . 6*31 



Lime 2*54 



Real ingredients . . 



99-88 

 7*31 



92-57 



