1882.] 
AMERICAN AGRICULTURIST. 
9 
A Bushel Box. 
Mr. “R. H.,” Orange Co., N. Y., makes a 
box in the following manner that holds just 
a bushel:—Cut a 12-inch pine board in foot 
lengths; these make the ends of the box, as 
shown in the engraving, made from Mr. 
“H.’s” sketch. The sides and bottom are 
made of strong lath 18‘/ 3 inches long and se¬ 
curely nailed to the end pieces. These boxes 
can be packed closely and are handy for har¬ 
vesting and marketing potatoes, apples, etc. 
A Lesson in Agricultural Chemistry- 
Something About Nitrogen. 
BY PROP. W. O. ATWATER, WESLEYAN UNIVERSITY, 
MIDDLETOWN, CONN. 
Chemistry tells us that air is composed 
mainly of two gases, Nitrogen and Oxygen. 
Each of these, like the air which they together 
make, is colorless and invisible. We can 
not see them, yet we feel them in every 
breeze, we breathe them in every breath, with¬ 
out them we should die. Air has weight. 
The atmosphere presses down upon the earth 
with a force of about 15 lbs. per square inch, 
or nearly 5,000 tons per acre. Four-fifths of 
this weight is nitrogen and one-fifth oxygen. 
Over every acre of land, then, there are nearly 
4,000 tons of nitrogen and 1,000 tons of oxy¬ 
gen. The oxygen is the active, and the nitro¬ 
gen the inactive element of the air. To make 
a fire bum, we provide a supply of air. It 
is the oxygen that supports the combustion. 
Close the draft, and as soon as the oxygen is 
used up the fire goes out. Nitrogen remains, 
but it cannot sustain the flame. We breathe 
air to support life. Here again oxygen is the 
efficient agent. The nitrogen dilutes the 
oxygen. In an atmosphere of pure oxygen 
respiration would be too active, but in one of 
pure nitrogen we should suffocate. And if 
we are in a perfectly close room we speedily 
consume the oxygen, and unless fresh air 
with its oxygen were supplied we should die. 
Where Nitrogen is Found. 
Everywhere, then, where air is, there is 
nitrogen. Not only in the atmosphere as it 
surrounds the whole earth, but in the waters 
of springs, streams, and the ocean which dis¬ 
solve air and hold it, and in the soil which the 
air likewise permeates, does the aerial nitrogen 
occur. But there is a great deal of nitrogen 
besides that in the air. Nitrogen forms a part 
of every plant, from the grass to the oak, and 
is in every organ, in root, stem, leaf, flower, 
fruit, and seed. It occurs in the body of every 
animal, and in every part of the body. 
Neither plants nor animals could live or even 
exist without it. It is an essential element 
of all our foods, and the costliest component 
of fertilizers. Its compounds are in earth, 
and air, and sea; in every fertile soil; in¬ 
deed no soil could be fertile without them. 
Free and Combined Nitrogen. 
I have just spoken of compounds of nitro¬ 
gen, and ought to explain the difference 
between nitrogen in the free or uncombined 
state, and in compounds. The nitrogen that 
makes up the bulk of the air, is in what 
chemists call the free state. The minute 
particles, atoms, as they are called, are not 
united to those of any other element, they 
exist by themselves. But they are capable 
of combining with other elements to form 
compounds. Thus an atom of nitrogen 
unites with three atoms of hydrogen to form 
a compound called ammonia, and two atoms 
of nitrogen combine with five atoms of 
oxygen to form a compound called nitric 
acid. So long as the nitrogen remains free,, 
neither plants nor animals can make the 
most complete use of it, but in its compounds 
it can be directly used as food by both ani¬ 
mals and plants. And the compounds of 
nitrogen are employed in a great variety of 
ways to supply the wants of man. 
Compounds of Nitrogen. 
The nitrogen compounds that are of most 
importance in daily life may be divided into 
three classes : Ammonia, Nitrates, and Or¬ 
ganic Nitrogen Compounds. 
Ammonia. —We know very well the intense¬ 
ly pungent odor of ammonia water, “ Spirits 
of Hartshorn.” This is due to ammonia. 
Ammonia is, like nitrogen, a colorless, in¬ 
visible gas. It is composed of two gases, 
nitrogen is one, the other is hydrogen, the 
gas which, combined with oxygen, forms wa¬ 
ter. Ammonia is formed when nitrogenous 
matters decay. We often find a strong smell 
of it in the stable and around the out-houses. 
Very minute quantities occur in the air, and 
we have it in concentrated forms, in smelling 
salts, Sal Ammoniac, and in Sulphate of Am¬ 
monia, which is so much used for a fertilizer. 
Nitrates.—Nitric Acids. —I have just 
said that two atoms of nitrogen may unite 
with five atoms of oxygen, and that the com¬ 
pound is called Nitric Acid. But the latest 
chemical theory requires that some water 
should be added to this to make the true 
nitric acid. This is in fact the case with the 
nitric acid which we buy of the apothecary 
as aqua fortis. If we take nitric acid and 
put soda with it, we get nitrate of soda, or 
soda saltpeter, as it is sometimes called. The 
nitrate of soda that is 60 much used for a 
fertilizer is an impure material brought by 
thousands of tons from Peru and Chili. 
Ordinary saltpeter, or “nitre,” is a nitrate of 
potash, that is, it consists of nitric acid and 
potash. Nitric acid in the soil combines with 
lime, making nitrate of lime. In this form 
nitrogen is leached out of the soil by water, 
carried beyond the reach of tho roots of 
the plants to streams and the sea, and thus 
the precious element is lost to vegetation. 
The loss of fertility which soils suffer by the 
washing away of nitrates is incalculable. 
Organic Nitrogen Compounds. —Nitrogen 
in ammonia, nitrates, and other forms, is 
gathered by plants from soil and air, and 
used by them as food. When it gets into the 
plants, it undergoes wonderful changes. It 
combines with other elements, carbon, oxy¬ 
gen, hydrogen, and so on, and these com¬ 
pounds are stored away in the different parts 
of the plant. Thus we have in wheat, the 
gluten, that boys like to chew in “wheat 
gum.” There are a great many such com¬ 
pounds in plants. Many of them are eaten 
by animals and are stored away in their 
bodies. The lean meat, skin, and connective 
tissues of our bodies, the albumen, white, of 
eggs, and the casein or curd of milk are 
nitrogen compounds, and are formed from 
similar compounds in plants. Now, the 
gluten of wheat, the casein of milk, the al¬ 
bumen and the fibrin of meat, and so on, are 
called organic compounds, and their nitrogen 
is organic nitrogen. 
The Nitrogen of the Atmosphere. 
We have already learned that four-fifths 
of the air is nitrogen, in the free state. The 
atmosphere also contains combined nitrogen, 
ammonia, nitrates, etc., but the quantities 
are extremely minute. Rain, snow, and dew 
bring nitrogen compounds to the soil, but in 
quantities so small as to do but little toward 
enriching it. That is to say, tho amount of 
ammonia and nitrates brought to the soil in 
this way in a year would be only a small part 
of what an ordinary crop would need, but in 
the course of a number of years quite a 
quantity might accumulate. Some chemists 
hold that the free nitrogen of the air is as¬ 
similated by the soil, but this is doubtful. 
The Nitrogen of the Soil. 
The nitrogen of the soil comes partly from 
the atmosphere and partly from vegetation, 
from the plants which have grown and been 
left to decay in it. The soil contains very 
little ammonia or nitrates. Nearly all its 
nitrogen is in the more complex form of or¬ 
ganic nitrogen. But the nitrogen in the soil 
is undergoing continual change. The organic 
nitrogen is altered, by “nitrification,” to 
nitric acid, and this nitric acid, unless seized 
upon by plants, is sooner or later carried 
away by water, and lost to vegetation. 
Nitrogen in Fertilizers. 
Natural manures, dung, urine, etc., contain 
scarcely any nitric acid, and but very little 
ammonia. Nearly all the nitrogen is in the 
form of organic nitrogen. It occurs as or¬ 
ganic nitrogen likewise in most of the arti¬ 
ficial fertilizers, as bone, dried blood, meat 
scrap, fish, leather-waste, and in the “am- 
moniated” phosphates, in which these are 
used to supply the nitrogen. Peruvian guano 
contains considerable ammonia, but the lar¬ 
ger part of the nitrogen is in organic com¬ 
pounds. Indeed in all ordinary nitrogenous 
fertilizers, except nitrate of soda and sulphate 
of ammonia, the bulk of the nitrogen is or¬ 
ganic nitrogen. 
What Forms of Nitrogen do Plants Use for Food? 
Plants can take their nitrogen as ammonia, 
as nitric acid, and as organic nitrogen. They 
Beem to prefer nitrates and ammonia. The 
number of organic nitrogen compounds 
which they are able to digest, so to speak, is 
limited. Practically the larger par t of the 
nitrogenous food of plants seems to consist of 
the nitric acid which their roots gather from 
the soil. This nitric acid is derived mostly 
from the decay of vegetable and animal re¬ 
mains in the soil, though part comes from 
the atmosphere in the forms of ammonia and 
nitric acid. The inert nitrogen compounds, 
which, until changed, are useless to the plant, 
are gradually altered by the process of nitrifi¬ 
cation above referred to, and finally reach 
the condition of ammonia and nitric acid, 
the forms which plants prefer. And not only 
is the vegetable matter of the soil thus worked 
over for the use of plants, but animal refuse, 
dung, guano, and the various materials used 
for fertilizers, including even ammonia, are 
transformed by nature in that wonderful 
laboratory which we call the soil, and made 
into the compounds best fitted for the plant. 
