Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1879-09-10
The Young Farmers Catechism.

VOLATILE OR AERIAL Plant FOOD.
Question--When vegetable matter is burned
nothing but the ash is left. What becomes
of the rest
Answer-It goes off into the air in the
form of smoke, vapor and gases.
Question-What is the smoke composed of
Ansper-Fine particles of unburned car
bon. Where the combustion is perfect there
is no smoke.
Question-What is the vapor?
Answer-Steam from evaporated water
contained in the burning matter.
Question-What are the gases
Answer--First in quantity are the car
bonic acid and carbonc oxyde gases, pro-
duced by the union of the oxygen of the
air with the carbon of the burning plant
substance. These constitute more than
three-fourths Of all the gaseous matter that
escapes. The uncombined sulphur which
the burning vegetable matter contains goes
off as sulphurous acid gas. Ammonia gas
and volatile ammonia compounds are also
thrown off in the burning of vegetable mat
ter, and also nitrous acid gas.
Question-How came these substances in
the plants
Answer-The carbon was absorbed from
the air by the leaves in the form of carbonic
acid gas, and was there, under the action of
the suns light and heat, united with the
other substances taken up by the roots and
transformed into organized plant material.
This was carried in the sap to all parts of
the plant, the different tissues absorbing and
appropriating what each needed for its
growth.
Question-Is any other kind of plant food
besides carbon taken in directly from the
atmosphere by the plant through its leaves
Answer-It has been believed that water,
nitrogen, and perhaps other matters, were
imbibed by the leaves and assimilated as
food by plants. But the weight Of opinion
now is that carbon only Tin the form of car.
bonic acid) is taken up by the leaves and
that all other sorts of plant food enter the
plant by the roots.
Question-How are these volatile substances
in the air brought within reach of the roots
of plants
Ansoer-The soil itself, when made open
to the passage of air through it by tillage
and undertaking, absorbs them to a con-
siderable extent from the air which comes
in contact with it, But most of this class
of plant-food is brought down in the rains
and SHOWS. The more rain and snow water,
therefore, that passes through the soil the
richer in this class of plant-food does that
soil become. The earth seizes upon these
substances with avidty, and the water be-
comes purified by its passage through thin
layer of soil. The earth has a greater az
finity for these things than water has, and
can take and bold them for the use of plants.
Thus tillage and undertaking, by allowing
the free passage of both air and water
through the soil, increase its fertility, that is,
its store of plantfood. 1t has been many
times proved in practice that good tillage
without manure will give better crops than
poor tillage with manure. This is especially
true of what are called heavy soils.
QuesfiOn--What are the most important
of the volatile plant foods taken in Though
the roots 81
Answer--The nitrogen compounds
Question-What are they
Answer-Ammonia composed of nitro
gen and hydrogen) and nisric acid (com
posed Of nitrogen and OXYGEN, with theil
salts.
Question What are the other sources
aside from the atmosphere, from which WI
obtain these
Anstoer-From all decaying animal ant
vegetable substances, and also as artificial
products. The former include green vege
tation turned under by the pillow, muck, dea'
leaves, straw, sea-weeds, sod, dead fish an,
other creatures, the dung and urine OF our dc
nestle animals and of rnan. The latter in
clude sulphate of ammonia produced in tn
distilation of bones, and of coal for making
gas, aud also the nitrates of potash and o
soda, extracted from the soil in rainless oil
mates. These are the nitric acid salts spoke
Of in the answer to the previous question.
Quesiion--Are these heterogeneous ferti
izers cheap and easily had 7
Ans~e-No, they are the most costly {
all we use and the most scarce, yet they al
absolutely necessary to the production {
our crops.
Question Which of our ordinary manur,
contains them in greatest abundance A?
Answer-Urine.
Question What then is the greatest was
Of our farms ?
Ansper--The waste Of the liquid manu-
Quesiion--Iiow is this wastedY
Anacer-By allowing the urine to be 10
and the solid manure to be leached by raiI