CHEMISTRY OF CARROTS. 



483 



The results show that, although the" carrot will grow 

 and be a productive crop on soils where neither mangold 

 nor turnips could be profitably cultivated, its mineral 

 requirements from the soil differ but little, either in in- 

 gredients or in quantity, from those required by the other 

 crops. This power of development, which renders the 

 carrot so valuable a crop on poor light soils, provided they 

 be of sufficient depth, is due to the mode in which the 

 plant sends down its tap-root into the soil, from the 

 depths of which it abstracts its necessary supplies of food- 

 materials, and brings them up to the surface elaborated 

 into the form of a nutritious, fleshy root. In deep sandy 

 loarns its tap-root has been found penetrating to a depth 

 of 10 to 12 feet; and even in the soils of the upper beds 

 of the lower oolite it has been traced threading the brashy 

 surface of the subjacent rock to a distance of 3 to 4 feet 

 from the thick part of the root, the diameter of the broken 

 end indicating that its range had been far greater than 

 had been traced. Assuming an equal weight of produce 

 per acre from a crop of turnips, of mangold, and of carrot 

 that is to say, of 20 tons of roots and 4 tons of tops 

 from each Messrs. Way and Ogston calculated that the 

 amount of mineral matters abstracted from the soil would 

 be respectively as follows: 



