72 
AMERICAN AGRICULTTJKISl 
The Back Volumes of the American Agriculturist, 
neatly bound, can now be supplied from the commence¬ 
ment. These of themselves constitute a beautiful and 
valuable Farmer’s Library, embracing a compendium 
of all the important agricultural articles that have ap- 
peareed during the last thirteen years. First ten volumes, 
new edition, furnished bound for $10. 
Bound volumes XI, XII and XIII (new series), $1 50 per 
volume ; unbound, $1 per volume. The whole fourteen 
volumes furnished bound for $14 50. 
^nterkmt ^Urkulturist. 
Ncw-York, Thursday, April 12. 
Sgjy This paper is never sent where it is 
not considered paid fot—and is in all cases 
stopped when the subscription runs out. 
We occasionally send a number to persons 
who are not subscribers. This is sometimes 
done as a compliment, and in other cases to 
invite examination. Those receiving such 
numbers are requested to look them over, and 
if convenient show them to a neighbor. 
Date Your Letters. —R. H. T. requests 
some missing numbers, but omits his Post- 
office, Town, and State, and the Postmaster 
has done the same on the envelop. We 
have an alphabetical list of Post-offices, but 
none of individual names. In this as in many 
such like cases, we are unable to comply 
with the request. 
AMOUNT OF SEED TO THE ACRE, 
It is impossible to give an arbitrary rule 
for the amount of seed, since there are so 
many circumstances to be taken into ac¬ 
count. Whereafter thinning is practicable, 
it is expedient to use seed liberally, but 
where this can not be done, we think the 
error is usually on the side of too thick sow¬ 
ing. Wheat, for example, if evenly sown 
and well covered, will do better with a small 
quantity of seed. The growth of both straw 
and grain will be larger if the plants be not 
too much crowded. 
The following give the smaller and larger 
quantities usually sown or planted upon an 
acre: 
Barley, broadcast, 14 to 24 bushels ; in 
drills, t to 14 bushels. Beans, 2 to 3 bush¬ 
els. Beets, 3 to 5 lbs. Buckwheat, 1 to 14 
bushels. Carrots, 2 to 24 lbs. Corn (Indi¬ 
an), 4 to 14 bushels ; Broom Corn, i to 14 
bushels. Flax, for seed, 4 to 1 bushel; for 
fiber, 14 to 24 bushels. Grasses—Red Clo¬ 
ver, 10 to 16 lbs ; White Clover, 4 to 8 lbs.; 
Blue grass (Kentucky), 10 to 16 lbs. ; Herds 
grass (Red Top), 12 to 18 quarts; Orchard 
grass, 20 to 30 lbs.; Timothy, 12 to 18 qts. 
Hemp, for seed, f to 1 bush.; for fiber, 1 to 
14 bush. Millet, 1 to 14 bush. Mustard, 10 
to 20 qts. Oats, 2 to 4 bush. Onions, 4 to 
5 lbs. Parsnips, 3 to 6.1bs. Peas, in drills, 
14 to 14 bush.; broadcast, 2 to 34 bush., ac¬ 
cording to size of seed. Peanuts, in hills or 
drills, 1 to 2 bush. Rye, in drills, 4 to 1 bush.; 
broadcast, 1 to 2 bush. Turnips, 14 to 24 lbs. 
Wheat, in drills, f to 14 bush.; broadcast, 14 
to 24 bushels. 
Beware of Damaged Guano. —We have 
been recently informed that parties in this 
ity have recently purchased damaged wet 
Guano at a low price, and are selling it for 
best Peruvian. We would caution all those 
wanting Guano to be careful what they pur¬ 
chase. 
CMEMSSTKf 
FOR SMALL AND LARGE BOYS AND GIRLS. 
CHAPTER XII. 
Combustion or Burning. 
91. Repeat the experiment last described 
(90), but use instead of the wood taper, one 
made of charcoal; or wind a small wire 
around a little piece of hard charcoal, ignite 
a single point of it, and then thrust it into • 
the vial or bottle of oxygen gas. It will 
burn very rapidly, throwing of!' brilliant 
sparks or scintillations. When all the oxy¬ 
gen is consumed the fire will go entirely out, 
and another piece of lighted coal thrust in 
will be extinguished as readily as if dipped 
into a vial of water. 
92. The burning is produced by the union 
of the oxygen with the coal (carbon)—two 
atoms of oxygen with one of carbon, C0 2 or 
COO—forming a new compound called car¬ 
bonic acid. This carbonic acid is a color¬ 
less gas, and is precisely the same as is 
sometimes found in the bottom of wells—or 
that which bubbles up from soda-water, or 
that formed in raising bread, and which fills 
the little interstices or holes that produce 
the lightness. On withdrawing the extin¬ 
guished coal from the vial, we shall find it 
has lost a portion of its bulk, and yet there 
is no trace of it to be seen in the vial. It has 
assumed a different form and become invis¬ 
ible. (See chapter i, sections 11 and 12, and 
read what is said of the three forms of mat¬ 
ter.) 
93. Let us try and understand where the 
heat comes from in this experiment, for we 
have supposed both the coal and oxygen to 
be cold. If we place a piece of cold iron on 
a blacksmith’s anvil, and strike it briskly 
with a hammer, it will soon become quite 
warm. The same would happen to other 
metals, or to a piece of wood. Take any 
substance and compress it suddenly and it 
will become warm to the touch. The ex¬ 
planation of this is, that heat (caloric) exists 
in two different states—in one state it is 
sensible to the touch, and in the other it is 
insensible. Thus, no heat was added to the 
iron on the anvil by striking it with a cold 
hammer, but some heat before insensible is 
brought out and made sensible by the ham¬ 
mering, because the iron is compressed into 
a smaller bulk. You can take a sponge 
which is apparently nearly dry, and by com¬ 
pressing it force out water. 
94. Take a metal syringe and close the 
small opening. Now force the piston down 
suddenly, so as to compress all the air it 
contains into a small space, and the metal 
around the compressed air will become quite 
warm. With proper care and a little prac¬ 
tice, this air may be made so hot by simply 
condensing it that it will set on fire a piece 
of tinder or'spunk (punk), previously put 
under the piston. 
95. Mingle together a gill of sulphuric 
acid, and a gill of water—both cold—and 
they will not fill a vessel holding two gills. 
A considerable condensation takes place, the 
two when together occupying less space 
than before ; and this condensation will 
bring out a large amount of sensible heat, 
just as in the case of condensing the iron 
with a hammer. 
96. On the contrary, when a substance ex¬ 
pands to occupy more space, it secretes or 
makes insensible a quantity of heat. An il¬ 
lustration of this is found in the ordinary 
process of mingling salt and snow or pow¬ 
dered ice, to produce cold. The salt and 
snow, or ice, melt and occupy more space 
and render insensible the heat before sens¬ 
ible. 
97. Did you never wonder where all the 
heat comes from, when you go into a cold 
room, on a cold day, with cold fuel and a 
cold match, and kindle a fire 1 We shall 
soon see. In the experiment above (91) the 
carbon (coal) and oxygen unite together, and 
form the carbonic acid gas which is nearly 
one and a half times as heavy as the oxygen. 
Here there is a condensation and some of 
the heat is squeezed out, so to speak, and 
becomes sensible or visible in heating the 
coal to a brilliant redness. 
98. Now what takes place in the vial, is 
just the same chemical action as is going on 
in our stoves, fire-places, lamps, candles, or 
wherever we are making insensible heat 
sensible by burning wood, coal, or other sub¬ 
stances. The air contains about one-fourth 
of its bulk of oxygen. Our charcoal or hard 
coal, is nearly pure carbon, and the oxygen 
of the air unites with this carbon to form 
condensed carbonic acid (C0 2 ), and the heat 
before insensible in the oxygen of air is 
made sensibe—we feel it in the warmth pro¬ 
duced. In fact, then, almost all the heat of 
fires comes from the air. No matter how 
cold the air is, we can make it give out heat 
by condensing it in a tube, or by uniting its 
oxygen with some combustible substance. 
99. Woody fiber is made up of 12 atoms 
of carbon, united with 10 atoms of oxygen 
and 10 atoms of hydrogen (C 12 O 10 H I0 ). But 
the 10 atoms of oxygen and 10 of hydro¬ 
gen, if separated from the carbon, will form 
just 10 atoms of water (HO). In burning 
wood this water is formed and escapes in 
vapor, whiclLgives the whitish appearance 
to the smoke, while the 12 atoms of carbon 
(coal) unite with 24 atoms of oxygen from 
the air and produce 12 atoms of carbonic acid 
(COo), which goes off in an invisible form 
and floats in the air till it is taken up by the 
leaves of trees or plants, and goes to form 
new wood, &c. Charcoal burners cover up 
a mass of wood with earth to keep out the 
greater portion of the air, and then the heat 
produced by allowing a little of the wood to 
burn, drives off the water, leaving the char¬ 
coal (carbon) behind. You see this water 
escaping in the white smoke over a charcoal 
pit. No particles of carbon rise up to give 
it a dark color, as sometimes happens in 
burning wood rapidly in the air. 
100. If we wish to make wood or coal 
burn faster, we blow it, or produce a draft of 
air, by means of a stove or chimney, so as to 
bring more air (or oxygen) in contact with 
the fuel, and produce a more rapid condens- 
