The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1849-11-10

are called upon to perform; only those
things then, can be used for food, which
contain those elements, and we find in the
human body, only differently combined,
the same elements which are present in
the grain used by us, and IN the grain and
grasses used by the animals which we con-
sumo for food. Those materials are of such
a nature, as they cannot exist but in the
soil. Plants must have them or they could
not serve for food, because without them
they could not supply the demands Of the
system wearing out by age; wearing out
by exercise. They cannot obtain them
from the air, they must get them from the
soil, or they cannot grow These particu-
lar things then arc necessary, because they
are the materials out of which plants are
made. This is one way by which we
know that particular things are necessary
: to produce crops.
Now, for the second. A particular soil
produces good crop. We ascertain Of
what that soil is composed and finding It
to contain particular substances, we con-
clude it is those substances which produce
the fertility. If in the examination OF many
l soils we still find these same constituents,
then our opinion as to their necessity is
confirmed. If now, a barren soil be ex-
amincd and we find some of those substan-
ces absent, then because no crop is pro-
duccd, we still more strongly believe in
their necessity to a fertile soil. II now,
we add that thing absent in barren soil
it, and find the soil by this addition to
BE- rendered productive, then, the most per-
toct conviction must be produced IN our
minds, that those substances always found
in plants, those substances whose elements
are found in the human body, those sub
stances Which always exist in fertile soil,
those substances of which some are absent
IN barren soils, and by the addition OF
which to these soils, fertility Is produced,
are the necessary absolutely necessary
causes Of fertility.
fertile soil then must contain all OF
these constituents, any one Qf rh'ct Jcirg
assent. rhatcrr may be The quantity of the
others, the soil 1riU be Lorycn. Now, how
can any one, save by chemical anay.
SIS, tell what is absent, or what is present!
and il he does not know, how can he add
only that which is necessary! He may
add what the soil already has in sufficient
abundance he may withhold wha, i has
not, and after long course Of ,rial, COR
stunning time, consuming labor, consuming
money, he hits on the right thing and
produces his crop. " hat is this inference
worth 10 another on different soil
nothing, absolutely nothing. A neighbor
VII! ny manure successful in the hand
OF his friend and derive no benefit from
1t so that no lesson of general utilly is
learned, no fact known of benefit to any,
save the particular individual upon the
soil where the experiment was tried.
One IN this way is denied even the poor
privilege Of learning by his errors, or
Of profting by failure. The source of
error is unknown, the cause of failure not
determined.
The substances entering INTO the COM
position OF soil are:
LIST Organic matter; that is: animal
and vegetable matter.
:. Silica !. c. sand.
3. Iron as an Oxide or rust Of the me-
tai.
4. Alumina i. c. Clay.
s. Line.
6. Magnesia.
7. Potash.
8. Soda.
9. Phosphoric Acid in combination
with some OF the foregoing, excep, the
sand or vegetable matter.
10 Sulphuric Ac,d, also in combination
with some of the foregoing, with the
same exception.
/ II. Chlorine, generally in combination
with the Potash or Soda.
There is also present in some soils, mang
anese, but is not of especial value. The
particular uses and properties Of these
different substances I will explain here
after. My object at present is TO demon
s'ratc the necessity OF knowing their
quantity Now, any one ofthese substan-
ces being absent or deficient, barDenness
must he the result. But can the par
ticular absence or deficiency of either be
i determined save by analysis. When you
ahentively consider, gentlemen, what !
have said. l am certain that despite OF
any preconceived notions on the subject,
your reflection, your reason, your com,
mon sense will convince you OF the great
advantage Of the science whose minister
| am, to the arr which you follow.
, And I ask you TO test every principle
which I shall inculcate by your own
jnd2ment; if they appear just and rea-
sonable, follow them. if they appear 9TH
prwise, reject them I shall give you
facts Which YOU yourselves cannot obtain
| Upon those facts You are as well quail
fed to form an opinion as any ore else.
GResults of examinations Of soil, belong
ing al this point in the lecture, will be
gwen hercafter.l