200 



Analyses of Ashes of Plants, 



The columns of this summary must tell their own tale — they 

 are replete with useful information, which will be more easily 

 furnished by inspection than by any description that could be 

 offered. We may simply say that, whilst they show a greater 

 similarity in mineral composition between the three roots than 

 could by possibility have been anticipated, the points of difference 

 are well worthy of attention. 



The Jerusalem, Artichoke. 



We are not acquainted with any very certain statistics of the 

 produce of this plant; and in order to calculate its power to exhaust 

 the soil, the proportion of stem and leaves to tuber should be 

 Imown. It is observable by the analysis that the ash of the 

 tuber contains very much potash, and far more phosphoric acid 

 than turnips, beet^ or carrot. The quantity of ash is also consi- 

 derable. 



The mineral composition of the tuber of the Jerusalem arti- 

 choke may be thus expressed : — 



Table 24. — Mineral Matter (in lbs.) in one ton of the Tuber of the 

 Jerusalem Artichoke. 



Silica 0-61 



Phosphoric acid . . .6*81 

 Sulphuric acid . . . 1'51 



Lime 1*34 



Magnesia . . . .0*52 

 Peroxide of iron . . .0*18 

 Potash . . . .22-40 



Soda — 



Chloride sodium ... — 

 Chloride potassium . . , 1 * 96 



35-33 



Here it will be seen that, weight for weight, this vegetable con- 

 tains nearly four times as much phosphoric acid, and three times 

 as much alkali, as turnips, beet, or carrot. The stems and leaves 

 are, in proportion to the tubers, too small to be of great im- 

 portance in the calculation ; and, as we have just said, we do not 

 possess at present the data necessary to include them. The stems 

 will, however, remove a notable quantity of potash. Taking into 

 consideration the large produce of this plant, and the little 

 manure or cultivation required by it, we are at a loss to see where 

 it obtains all this alkaline phosphate, unless, like the carrot, it is 

 possessed of superior powers of acquiring mineral sustenance. 



