1846. THE CULTIVATOR. ^ 307 
Amber, according to scientific authority, is the tur¬ 
pentine of unknown trees belonging to a former geolo¬ 
gical epoch. 
Butter. —This substance is a mixture of six different 
fats, viz., common stearine, margarine, and oleine, with 
butyrine, caprbine, and caprine. Keeping butter after 
melted, at a temperature of 68° for some days, the stea¬ 
rine and margarine crystallize, white the other remains 
liquid. Oleine is separated by solution in alcohol; the 
others by successive solutions in the same, as they pos¬ 
sess different degrees of solubility, but have not been 
obtained pure. 
Coloring Matter of Plants. —The green color of 
plants is due to the presence of a substance termed Chlo¬ 
rophyll. But so excessive is its coloring power, that 
even very deeply colored plants contain very little of it; 
and Berzelius calculated that the entire mass of leaves 
of a large tree seldom contains ten grains of this sub¬ 
stance. Its composition has not been fully ascertained, 
though it contains no nitrogen. The coloring matter 
of flowers, from its very minute quantity, it is almost 
impossible to examine. 
Kreosote. —This is the antiseptic principle in pyro¬ 
ligneous acid, and in the smoke of burning vegetable sub¬ 
stances. Its most remarkable property is,that it coagulates 
albumen and the coloring matter of the blood, and these 
bodies are then no longer susceptible of putrefaction. Fi- 
brine, or muscular flesh, immersed in a solution of kre¬ 
osote for some minutes, has no tendency to putrefy even 
if exposed to the heat of the sun. Kreosote has a simi¬ 
lar action on vegetable substances; hence fence posts, 
immersed in pyroligneous acid, are rendered very du¬ 
rable. 
Cocoa-tallow. —The albumen of the cocoa nut con¬ 
tains a solid fat, which is extracted from it, and used in 
the manufacture of candles. It is a mixture of ordinary 
oleine with a stearine, which contains a peculiar acid, 
called cocoa stearic acid. 
Nutritive value of Food. —Boussingault has shown 
by experiments, that in herbivorous animals, the total 
quantity of nitrogen assimilated for the growth of its 
muscular aud other tissues, is derived from, and equal to 
that contained in the vegetable substances used as food; 
and that hence, to ascertain the nutritive value of any 
organic substance, it is only requisite to determine the 
quantity of nitrogen it contains. A table is given in 
No. 12 of the last volume of the Cultivator, exhibiting 
the agreement of theoretical results thus derived, with 
those of many experiments directed by enlightened agri¬ 
culturists. 
Source of Nitrogen. —Plants vary exceedingly in 
the facility with which they derive nitrogen from the air, 
whether by direct absorption of the gas or as ammonia. 
Thus some species of Trifolium, or trefoil or clover, 
thrive nearly as well when placed in pure sand, and sup¬ 
plied with air and water only, as when sown in ordinary 
soil; but on the contrary, wheat grows but slowly under 
the same circumstances, and makes no attempt to flower; 
and on analysis, the whole plant is found to contain even 
less nitrogen in actual quantity than had originallyexisted 
in the seed. Wheat, therefore, has no power to absorb 
nitrogen from the air,while trefoil possesses that charac¬ 
ter in probably its greatest vigor. But fully grown wheat 
is rich in nitrogen; its seeds contain more gluten (which 
consists in part of nitrogen) than that of any other 
grain. Wheat derives its nitrogen from the soil; clover, 
trefoil and peas, mainly from the air. Hence, a crop 
of wheat containing a hundred pounds of nitrogen, ex¬ 
hausts the soil much more than a crop of clover con¬ 
taining a hundred pounds of nitrogen. Hence also the 
eminent utility of clover as a green crop to precede 
wheat; it draws wealth from the air, and reduces it to a 
shape in which wheat can use it. 
Nitrogen in a crop of Hay. —Hay contains usually 
about 1± per cent of nitrogen, or a ton contains 30 pounds. 
A good meadow, therefore, yields about 60 pounds of 
nitrogen per acre per annum. 
Animal heat. —The source of animal heat has great¬ 
ly puzzled philosophers. It appears to result mainly 
from the conversion of carbon into carbonic acid, by 
the union with oxygen in respiration, on the same prin¬ 
ciple that heat is developed in slow r combustion. This 
is proved by the fact, that the temperature is highest in 
red-blooded animals, and in the same animal,, at those 
periods when the circulation is most rapid and the quan¬ 
tity of air consumed the greatest, as in running or hard 
exercise. Only eight-tenths of the animal heat can be 
accounted for in this way; that is, the combustion of a 
given quantity of carbon is found to produce only eight- 
tenths of the heat of the body, during the consumption 
of that quantity in respiration. The rest must therefore 
be attributed to some action of the system itself. 
Gastric Juice. —The singular solvent energies of 
gastric juice has led to much inquiry as to its composition. 
It is specially characterized by a mixture of a quantity of 
free muriatic acid, with some salts. But if we form artifi¬ 
cial gastric juice, by mixing together the muriatic acid 
and the salts in the proper proportions, it is found total¬ 
ly incapable of dissolving the materials of food, as in 
digestion. The organic material of the gastric juice, 
though in very small quantity in any case, is wanting; 
but all the solvent powers of the natural juice may be 
at once conferred upon the artificial, by the addition of 
a very small quantity of the mucus of the stomach. 
Perspiration of Plants. —Dr. Hales planted a sun¬ 
flower feet high in a garden pot, which he covered 
with thin milted lead, cementing all the joints so that 
no vapor could escape, except through the sides of the 
pot and through the plant itself; but providing an aper¬ 
ture, capable of being stopped, through which the earth 
in the pot could be watered. He found, in fifteen days, 
after making all necessary allowances for Avaste, that this 
plant, 3| feet high, and Avith a surface of 5616 square 
inches aboveground, had perspired in twelve hours of a 
dry warm day, 30 ounces; on another day less dry, 20 
ounces; on a dry warm night, without dew, 3 ounces; 
and on a night with some dew, nothing. When there 
was rain or copious dew, the plant absorbed two or 
three ounces. 
Force of Sap. —Braddick, a British physiologist, eat 
off the stem of a grape, five years old, and covered the 
wound with a piece of bladder, secured by cement and 
twine. The bladder, although at first drawn very close 
to the top of the shoot, soon began to stretch, and to 
rise like a ball over the wound, and feeling as hard as 
a cricket ball. In about 48 hours afterwards the force 
of the sap burst the bladder. 
Century Plant. —The American Aloe, or Agave 
americana, is popularly supposed to flower only when 
a hundred years old, whence its name. But if subjected 
to the best treatment, it will flower in thirty years; on 
the other hand if badly managed, it will not flower in 
a hundred years. 
Difference in temperature for Plants. —Some 
tropical plants do not flourish and perfect their fruit in 
temperate climates, even if kept in the warmest hot¬ 
houses the year through. On the other hand, Yon Baer 
found Ranunculus nivalis and Oxyria reniformis flower¬ 
ing in Nova Zembla, where the soil was not Avarmed 
above 34£ degrees; and in Jakutsk, Erdman states that 
summer wheat, rye, cabbages, turneps, radishes and po¬ 
tatoes, are cultivated, although the ground is not thaw¬ 
ed in summer more than three feet in depth. 
Frost in Valleys. —Professor Daniel states, that he 
has seen a difference of 30°, on the same night, between 
two thermometers, placed, one in a valley, and the other 
on a gentle eminence, in favor of the latter. 
Advantage of Garden Irrigation. — Professor 
Lindley says, that mildew, often produced by dry air 
acting upon a delicate surface of vegetable tissue, is com¬ 
pletely prevented in annuals by very abundant waterings. 
The ravages of the Bolrytis effusa, Avhich attacks spi¬ 
nach; of Acrosporium monilioides, on the onion; and 
the mildew of the pea, caused by the ravages of Eri- 
syphe communis, all minute parasitic plants, may all be 
stopped or prevented by abundant Avatering in dry Avea- 
ther. 
Bice Paper is not prepared from the rice grain, but 
is the production of the solah, an aquatic plant Avhich 
grows profusely in all the marshes of China. 
