Sacramento daily record-union., 1882-01-28
AGRICULTURAL PAPERS.
A SERIES PREPARED ESPECIALLY FoR
THE "RECoRD-UaIoE"
Presenting the Instruction Contained in
Lectures from the Chair of agri-
culture, State University.
THIRD PApER-THE COMPOUNDS OF ELE
MENTs THAT CONSTITUTE THE BASIS
OF PLANS.

compound. This secondary compound may
have some general resemblance to one or
more of its constituents, and again it may,
and generally has, no resemblance to any of
them. have already pointed cut the diff
ference between mixture and chemical
compound, and this distinction must al.
WAYS be borne in mind In chemistry the
terms atom and molecule are In general use
to denote different conditions of matter.
An atom is the smallest portion OF an ele
ment whicn can enter into chemical com
bination. A molecnle is the smallest guam
tlty of matter which can exist in a free
state. An atom being the smallest portion
of an element, is literally indivisible; while
molecule Is . very small quantity OF
matter" which consists of an aggregation
of atoms, and hence it is divislble into Its
constituent elements. An atom IS the
smallest portion of an element; molecule
is the smallest portion of compound.
An atom is an indivi.ible whole MOLE
cule is divisible whole, consisting of a
collection of atoms.
To illustrate Two atoms OF hydrogen
and ore atom of oxygen combine
TO form one molecue of water. This
molecule of water is the smallest
portion of free water which can exist !;
but yet it may be divided into its con-
stituent elements, hydrogen and oxygen.
II two parts by measurement of hydrogen
and one part of oxygen are put in glass
! vessel and an electric spark passed through
them, there will be an explosive chemical
combination, and in the place of the gases
we will have few drops of water. This
is the synthetical method of analysis, i. e.
the putting together of two or more ele-
ments to form a body. If, on the other
hand, portion of water is taken, and by
chemical means decop posed into its con-
stituent elements, hydrogen and oxygen,
we make use of an analytical analysis,
which may be defined as the separation of
compound into its constituent elements.
The atomic eights of the different ele-
ments is the proportion by weight in which
they combine with one another. Hydro.
gen, being the lightest of all known ele-
ments, is taken as the standard of COM
pariscn, and its atomic weight has been
fixed as l. The atomic weights of carbon,
oxygen, nitrogen and sulphur are respect
lNSty l.. 10, ii anu duu
that if a vessel be filled with hydrogen gas,
at given temperature and barometric
pressure, and this gas be weighed, and if
then it be filled successively with carbon,
nitrogen, oxygen and sulphur, under the
same conditions of temperature and press
ure, and these different gases be also
weighed. it will be found that the vessel
full of carbon gas weighs II times as much
as the same bulk of hydrogen oxygen
weighed Is times as much, nitrogen IA
times as much, and sulphur 81 times as
much as hydrogen.
The molecular weight of compound is
the sum of the weights of the whole num-
Der OF atoms which constitute it. For in
stance, water contains two atoms of hy-
drogen and one atom of oxygen. Now
one atom of hydrogen weighs |, and two
atoms would weigh 2; one atom of oxy
gen weighs l6 times the atomic weight Of
hydrogen. SO the sum of the atomic
weights of two atoms of hydrogen and one
of oxygen would be 2xl6, which is Is, and
is the molecular weight OF water.
We may now study the organic CON-
pounds which make up the vegetable
structure, and which are produced from
the elements carbon, oxygen, hydrogen,
nitrogen, sulphur and phosphorus, by the
united agency of chemical and vital forces.
The number of distinctive substances to be
found in plants is practically illimitable,
and hundreds Of varieties and kinds of
compounds are already known to chemists.
While every plant is made up of great
nun. Der OF substances. many OF them con-
tain some organic compound peculiar to
themselves. In tea aud coffee we have an
active substance called theme, which con-
stitutes the active principle of coffee and
tea. The active substance of tobacco is an
oily liquid known in chemistry as nicotine,
and is narcotic and deadly poison. One
drop of pure nicotine is sufficient to kill
large dog. Notwithstanding the innumer-
able bodies in the vegetable kingdom, the
bulk of plants is made up mostly OF what
are called the proximate elements. These
are six IN number, and are ~ water; ~
the scellulose group or amyloids, consist
ing of cellulose woody fiber), starch, the
sugars and gums (3) the pectose group,
the pulp and jellies of fruits and certain
roots a. the vegetable acids ; (5) the fats
and oils and (6) the albuminoide rproteins
bodies. 1t will be necessary to describe
briefly each of these six elementary classes.
Water is the most abundant Ingredient
of plants. 1t exists in all parts of the
plant, and is not only essential to the life
of the plant, but is also the cause of the
succulence of its tender parts. Toe amount
of water in different plants varies it is
greatest in turnips and cabbage, in which
it is respectively 81 and so per cent. Of the
weight of the green plants. In pine wood
it is about 40 per cent; and in the potato
IS per cent. of the gross weight. Water
constitutes the sap of plants, and in green
plants is perceptible to the senses of sight
and touch. We may subject matter to two
stages of drying-they maybe frat dried in
the air, and are then said to be air dried
after being air dried they may be dried fur
ther by artificial heat. The water remain
ing in plants after being air dried is called
the bygroscopic water of vegetation
Flour, starch, sugar, and in fact about all
bodies, contain an appreclable amount OF
Microscopic moisture, which may be re-
moved by heat. Hay contains from l3 to
II per cent, small grains about IA
per cent, kernels of corn II per cent,
and pine wood about 2 per cent. of hygro-
scopic moisture. OF course the amount of
water evaporated by natural heat depends
on the temperature, and on that account is
more or less variable.
Cellulose is the water walls or coating of
the microscopic cells which go to make up
the framework of all plants. These cells
consist of minute sacks or closed tubes ad-
herring to one another. Cellulose is gen.
eral ingredient of all parts of all plants, but
is most abundant in the leaves and stems.
1t forms large portion of the husk or bran
of seeds, as well as being an ingredient, to
small extent, of the kernel. The fbers
OF cotton, hemp and fax are simply long,
thick. walled cells, and the cloth ar d unsized
paper made from these fbers are almost
pure cellulose. When pure, cellulose is
white, often silky or spongy, translucent
body, which swells up in water from the
absorption of moisture. Celluiose is insol-
uble in water, alcohol, ether and oils. A
very pretty application Of this insolubility
of cellulose is made use of in making the
g skeletonized leaves, fruits, ETC., which
make up the phantom bouquets. The
soft and fleshy portion of the leaves and
fruit is dissolved away, by treating the OBJ