of different kinds of Vegetable Food. 367 



substances made by the distinguished French chemist, differ 

 no further from each other than might be expected from pro- 

 ductions of the same vegetable variety grown on different 

 soils. 



Buckwheat {Polygonum Fagopyrum) constitutes an excep- 

 tion to this remark. In the table of analytical results* this 

 grain has a nitrogen per-centage of 2*40, while two ordinary 

 varieties of wheat {Triticum vulgar e) have 2*33 and 2*30 per 

 cent. Buckwheat meal from Vienna gave, as shown below, 

 1*08 per cent. Buckwheat grains {Polygonum tartaricum) 

 from the experimental field of Hohenheim Agricultural Insti- 

 tute, gave 1*56 per cent, of nitrogen, while the analysis of 

 three superior varieties of wheat grown in the same field, gave 

 respectively 2*59, 2*68 and 2*69 per cent. This species of 

 buckwheat was further found to contain 22*66 per cent, of 

 woody fibre. 



The equivalent value of buckwheat, according to Boussin- 

 gault, wheat being 100, is 108. The following analyses gave 

 for its equivalent value 170 ; for that of the Vienna buckwheat 

 meal 245. 



For the following investigation, the meals, table-peas and 

 beans and lentils, were procured by Prof, von Liebig from 

 Vienna. The grains, with the exception of rice and Triticum 

 monococcuni) were furnished from the Agricultural Institute at 

 Hohenheim in the kingdom of Wurtemberg, in reply to an 

 order for the most approved varieties of Cerealia cultivated in 

 Europe. The roots were from Giessen. 



The several grains, meals and roots, in their market con- 

 dition, were dried in a water-bath at 100° C. The potatoes, 

 beets, carrots and turnips, were cut into thin shavings with 

 the least delay, weighed between watch-glasses and placed in 

 the water- bath. 



The combustions for carbon and hydrogen were made with 

 oxide of copper, a mixture of chlorate of potassa and oxide 

 having been placed at the extreme end of the combustion- 

 tube. 



It was found difficult to reduce the woody fibre of the oats, 

 barley and buckwheat, to the requisite fineness for a complete 

 combustion. Where the difficulty could not readily be over- 

 come, in addition to the chlorate of potassa at the end of the 

 tube, it was found well, in filling with mixed substances and 

 oxide of copper, to add, at intervals of an inch and a half, 

 a small quantity of finely pulverized and thoroughly mixed 

 oxide of copper and chlorate of potassa. The successive evo- 

 lutions of oxygen in this case thoroughly reoxidized any por- 

 * Boussingault's Landsivirthschaft, Germ, ed., p. 294. 



