The Florida agriculturist. [volume] (DeLand, Fla.) 1878-1911, 1878-06-19

carbonate of lime. BY heating lime
stone the carbonic acid is driven off.
and lime is left in its common caustic
unslaked form.
Wdgnesid is the oxide OF the metal
magnesium. The calcined magne-
STA F" of the apothecaries is impure
magnesia, with the carbonic acid ex-
PEELED. Iron is the same element,
whether found in plants, manures, or
soils, in which it invariably occurs in
very small proportions as an oxide,
or in the various ores from which it
is manufactured on a large scale.
tSi3ic0.-Quartz, or rock crystal"
is pure silica. Flint is nearly pure
silica. Silica combined with various
other elements, makes up the larger
part OF the rocks and minerals of the
globe. Sharp sand consists chiefly
OF silica.
Sulpharic -Acid.-Sulphur is famil-
lar to every one in the forms of
birthstone and flowers of sulphur.
Sulphur united with oxygen, forms
sulphuric oxide, or, as it is more fire.
quently called, sulphuric acid. The
ordinary sulphuric acid of commerce,
called 'Oil of Vitriol," and used in
making superphosphates, consists of
sulphuric oxide with q small proper
ton of water
Sulphdtes.-If sulphuric acid and
lime are mixed together, they will
unite and form chemical compound,
s,ell,hate Of lime. Gypsum or plas-
ter is a more OF less impure sulphate
of lime. Sulphuric acid and mag
nesia make suIphdte Of magaesiG,
which we know as Epson Salts; it
occurs in some of the German Pot
ash Salts. So sutohdte Of soda con-
sists of sulphuric acid and soda. S"l-
plate ct potash, the basis of the best
potash salts, used as fertilizers, con-
sists of sulphuric acid united to
potassa. SuIohdte Of ammonia,
which is valuable fertilizer, consists
of ammonia and suIphuric acid
Pho$phoric .1cid-Phosphorus is
the material which is used for the
tips Of friction matches, and causes
them to shine when rubbed in the
dark 1t burns very easily, and in so
doing unites with the oxygen of the
air, and forms phosphoric oxide, or
phosphoric acid.
Mosphotes.-Just as sulphuric acid
combines with lime, potash, and
other bases to make sulphates, so
Phosphoric Acid unites with the
same basis to form phosphates. Phos-
phate of lime is the most important
4 of the phosphates. 1t is the basis o
I bone When bones are burned, the
water and organic (animaT matter
are driven off, and we have left the
bone-ash, which is nearly pure phos
phate of lime The South Carolina
| Navassa Canada, and other fossil and
mineral phosphates, which are used
for fertilizers, contain more or less
earthly matters mixed with the phos-
phate of lime.
WHENCE PLANTS OBTAIN THEIR SUP
PLIES OF FOOD.
| Plants get part Of their food from
the air, through their leaves and
other green parts, the rest from the
soil through their roots. This is
proven by vast amount of labori,
Gus and accurate experimenting, car
ried on, for the most part, in the
European Experiment Stations, for
the purpose Of discovering the laws
of plant nutrition and growth.
JVater.-Plants have the power OF
absorbing water through their leaves,
but the bulk of their supply comes,
and must come, from the atmosphere
to the soil, and thence to the plant
through its roots.
Orgonic Notter-Carbon, Oxygen
and Hydrogen. = The carbon of
plants is taken from the atmosphere.
The leaves absorb carbonic acid, and
with the aid of light wrest its carbon
and oxygen asunder, setting oxygen
free, and thus purifying the air, while
they retain the carbon. Carbon
unites with hydrogen, oxygen and
nitrogen, to make up the various
tissues of the plant, the root, stem,
leaf, and seed, the wood and bark,
the gluten, starch, sugar and so on.
The atmosphere supplies carbon far
in excess Of the demands of plants.
The best experiments indicate that
the carbon is all, or nearly all, OBJ
tanned from the air. The source of
the oxygen and hydrogen is not def
nitely settled. 1t is very probable
that the water absorbed through the
roots is the main, if not the entire
source of supply.
| N;fro0e., Our cultivatad nlon+s