IIORTUS GRAMINEUS \VOi3UllN EN SIS. 261 



matters of the soil are the only constituents wherein a sensi- 

 ble loss is perceived. 



M. Braconnot grew plants in substances free from any- 

 kind of soil, as in flowers of sulphur, and in metal. lie 

 supplied the plants with distilled water only. They arrived, 

 by these means, to a perfect state of maturity. The produce 

 was submitted to careful analysis ; and the results showed 

 that the different vegetables so produced, contained all the 

 constituents of the different species, precisely the same 

 as vvhen the plants were cultivated on their natural soils. 



[Some have supposed that the antipathy of plants arises 

 from the roots depositing a noxious matter in the soil. This 

 is a new theory, and pretty generally adopted by scientific 

 men, but by few practical farmers. Whether the land be 

 exhausted or poisoned by a previous crop, the remedy is the 

 same, whatever the real cause may be ; namely, a chanoe of 

 crops, and fresh supplies of manure. — Ed.] 



The analysis of a plant, therefore, and of the soil which 

 produced it, appear insufficient to account for the true cause 

 of the impoverishing principle of vegetables to the soil, and 

 why one species should exhaust it more than another. 



Some useful information, however, on this very interesting- 

 point, may probably be drawn from facts obtained by daily 

 practice and observation in the garden and the farm. 



Nutritive 

 Green Food. Matter, 

 lbs. lbs. 



Mangel-wurzel, or wdiite beet (beta cicla), 



produces upon a suitable soil, or a deep 



rich loam, on an average, twenty-five 



tons of green food per acre, every pound 



weight of which contains 390 grains of 



nutritive matter ; and therefore per acre. 56,000 3, 1 20 

 Carrots (daucus carola), produce upon a 



deep light loam, on an average, eleven 



tons, every pound of which contains 



750 grains of nutritive matter 24,640 2,640 



Potatoes {solainim tuberosum), produce 



upon a fresh loam, of intermediate qua- 

 lity as to moisture and dryness, on an 



