1817. 
THE CULTIVATOR. 
171 
VALUE OF DIFFERENT KINDS OF VEGETABLE FOOD, 
BASED UPON THEIR PER CENTAGE OF NITROGEN. 
BY EBEN N. HORSFORD, A. M., 
Rumford Professor of Application of Science to the Arts, in the University at Cambridge, Mass. 
Introduction. 
Since Gay-Lussac’s discovery of nitrogen in the seeds 
of plants, the conception of animal nutrition has been 
assuming a more and more definite character. 
Already had the principal proximate ingredients of 
meals, by taking advantage of their physical properties, 
been separated from each other; gluten, albumen and 
legumin, starch, gum, sugar, dextrine, and woody fibre 
were known, and their physical, as well as some of 
their chemical properties,* had been studied. 
Their more accurate chemical constitution was reserved 
to a later period, when the interesting disclosure was 
made, that they may be arranged in two classes, those 
containing nitrogen, and those containing no nitrogen; 
and that the former as well as the latter are, among 
themselves, nearly identical in composition. 
It is well known that laborers, supplied only with 
food containing no nitrogen, become incapable of exe¬ 
cuting their tasks; and further, that the corporeal sys¬ 
tem, even without labor, cannot be sustained upon such 
food. The discovery of the near identity in chemical 
composition between vegetable albumen, fibrin, and 
easeine, and the corresponding bodies found in the ani¬ 
mal kingdom, gave the above facts their explanation. 
The food must contain an ingredient suited to replace 
the animal matter consumed. 
This being known, and the quantitative relation of the 
several elements of the nitrogenous compounds being 
also known, an estimate of the value of give'n kinds of 
food, becomes, in the hands of the chemist, a problem of 
comparatively easy solution. 
Object of Investigation. 
The following investigation, undertaken, at the sug¬ 
gestion, and under the direction of Prof,. V. Liebig, in the 
Giessen Laboratory, had for its object the determination 
of the relative values of different kinds of vegetable food. 
These values are threefold. 
The various forms of food derived from grains, her¬ 
bage, and roots, furnish, 1st, bodies containing nitrogen; 
2d, bodies destitute of nitrogen; and 3d, inorganic salts, 
—all of which are serviceable in the animal economy. 
The nitrogenous bodies, from their solution in the 
Dlood, form the tissues—the actual organism. The 
bodies wanting nitrogen contribute, by their more or 
less perfect combustion, to the warmth of the animal body; 
and the salts of the alkalies and alkaline earths, serve 
in building up the osseous framework, beside constituting 
an essential part of every organ of the animal system. 
Their values for the latter purpose are in proportion 
to the phosphates the ashes contain. 
Their values for the second purpose above-mentioned, 
may be considered, in general, as in the inverted rela¬ 
tion of their values for the first;—since the larger the 
proportion of nitrogenous bodies, the less must be the 
proportion of bodies wanting nitrogen. 
Their values for the first purpose, that of ministering 
to the support and growth of organic tissues, have been 
the specific object of the hereafter enumerated deter¬ 
minations. 
* Fr. Marcet found gluten consisting of 55.7 per cent, of carbon, 
82.0 per cent, of oxygen, 7.8 per cent, of hydrogen, and 14.5 per 
Cent of nitrogen.— Annal. de Chim. et de Physiq., xxxvi., p. 27. ■ 
Previous Labor. 
Boussingault, to whom the agriculturist is so larged 
indebted for practical researches bearing upon the int e " 
rests of husbandry, has not left this field untrodden. T 
was thought, however, that the worth of his table of 
nutrition from the vegetable kingdom, could lose nothing 
by a series of carefully conducted analyses, embracing 
the chief varieties of vegetable food consumed by men. 
It was, moreover, conceived, that in substances contain¬ 
ing so small a per centage of nitrogen as grains and 
roots generally, the method of Messrs. Varrentrapp 
and Will for determining nitrogen, would give more 
accurate results than that of Dumas, employed by 
Boussingault. The analyses hereafter given, of the 
same substance, rarely varied from each other more 
than one-tenth of one per cent.; and yet the determina¬ 
tions which follow, and those of similar substances made 
by the distinguished French chemist, in general differ 
no farther from each other' than might be expected, 
from productions of the saihe vegetable species, grown 
on different soils. 
Buckwheat, ( Polygonum fagopyrum) constitutes an 
exception to this remark. In the table of analytical re¬ 
sults, page 294, BoussingaultV Economie Rurale, 
(Ger. Edition,) this grain has a nitrogen per centage of 
2.40, while two ordinary varieties of wheat ( Triticum 
vulgare ) have 2.33 and 2.30 per gent. Buckwheat 
meal from Vienna gave, as shown below, 1.08 per cent. 
Buckwheat grains ( Polygonum Tartaricum) from the 
experimental field of the Hohenheim Agricultural Insti¬ 
tute, gave 1.56 per cent, of nitrogen, while the analy¬ 
ses of three superior varieties of wheat, grown in the 
same field, gave respectively, 2.59, 2.68, and 2.69 
percents. This species was further found to contain 
22.66 per cent, of woody fibre. 
The equivalent* value of buckwheat, according to 
Boussingault, wheat being 1.00, is 1.08. The follow¬ 
ing analyses give, for its equivalent value, 1.70. For 
that of the Vienna buckwheat meal, 2.45. 
Grains and Roots—where procured. 
For the following investigation, the meals, table 
peas and beans, and lentils, were procured by Prof, 
v. Liebig, from Vienna. The grains, with the excep¬ 
tion of rice and Triticum monococcum , were furnished 
from the cabinet of the Hohenheim Agricultural Insti¬ 
tute, in the kingdom of Wurtemberg, in reply to a re¬ 
quest for the most approved sorts of cerealia cultivated 
in Europe. The roots were from Giessen. 
Mode of Investigation. 
The several meals, grains, and roots, in their market 
condition, were dried in a water bath, at 100° C., 
(212 Fah.) 
In drying the potatoes, beets, carrots, and turneps, 
care was taken to cut as thin shavings as possible, 
which with the least delay were placed singly upon 
watch-glasses, weighed and seated in the water-bath. 
For carbon and hydrogen, the combustions were made 
with oxide of copper, a mixture of chlorate of potash 
* By equivalent is meant that which may replace—or is equ& 
to in value. In this case, it signifies the equal in value as food. 
