134 ROOT CROPS. 



gum during germination, goes into the young shoot; 

 subtracting, of course, much from the nutritive quali- 

 ties of the tuber. 



The turnip abounds still more in water than the po- 

 tato. The proportion given by Boussingault, is nine- 

 tenths of its whole weight : other authors agree in 

 making it about the same quantity. The remaining 

 tenth contains woody fibre, a little oily substance, 

 some gum, and about one per cent of nitrogenous com- 

 pound. There is nothing more than a trace of starch, 

 but a small percentage of a substance called pedine, 

 which seems to answer the same purpose in feeding. 



The mangold-wurtzel, the carrot, the beet, and the 

 parsnip, all contain in their fresh state from 85 to 90 

 per cent of water. The parsnip and the carrot have 

 a little more of nitrogenous compounds than the 

 others. The sugar-beet, according to Payen, has about 

 10 per cent of sugar; carrots and parsnips, which are 

 also quite sweet, have from 5 to 7 per cent. In nearly 

 all of these roots, there are small quantities of starch, 

 gum, and oily matter. 



Such facts as the above may seem to place thes6 

 crops very low in the scale, as to their nutritive pro- 

 perties; but before we decide this question, we must 

 consider the amount that is produced per acre. 



a. Twenty-five tons of turnips is not an uncommon 

 crop on good land: if these contain but 10 lbs. of 

 solid matter in every 100, the aggregate amount from 

 25 tons would be 5000 lbs. 



b. Thirty bushels of wheat to the acre, at 60 lbs. 

 per bushel, would only give 1800 lbs. The dry mat- 

 ter of the turnip is nearly as nutritious as wheaten 

 flour, and we see from the above that there would be 

 nearly three times as much of it. If we take some 

 of the other roots, which produce quite as large a 

 weight per acre and contain less w^ater, the comparison 

 will be still ftore favorable to root crops. 



