The Marietta journal. [volume] (Marietta, Ga.) 1866-1909, 1902-12-25

in at one eEd OF the machine and the
dry cakes come out at the other, when
they are ground TO a powder and sack.
ed ready for market This blood will
usually contain about thirteen per cent,
OF nitrogen. which is the equivalent al
about sixteen per cent of ammonia,
but as in the case of the cotton-seed
meal. there IL actually no ammonia In
It,
TANKAGE.
The next important product of the
slaughter-house is whwat Is known to
the fertilizer trade as "Tankage"
This Is a mixture of blood. bones,
waste scraps Of meat. etc. This ma.
terial gets its name from the
fact that 1t is cooked in huge
tanks In the hrst preparation. 1t is
cooked under steam pressure at
high temperature for several hours.
AS result, most of the fat In the mass
Ia melted and rises to the top OF the
tanks, where 1t is skinned off and
utilized for soap-making and other pur.
poses, The bones and the cooked
meat, ETC., now lie at the bottom of the
tank, and the tank water is dark and
! highly colored-ls in fact a sort Of
soup. containing heterogeneous matter in
solution. The solid matter, bones, etc,
are removed and crushed or ground In
the same way as was done with the
dried blood product.
CONCENTRATED TANKAoE.
The tank water is run into vacuum
evaporation, the excess of water re.
moved, and product known as Con
centrated Tankage" Is the final result
OF the treatment. The finished mater.
ial contains about twelve per cent. Of
nitrogen. The dried and ground Bone
Tankage. or what is known as simply
Tankage, contains about seven per
cent. OF nitrogen. ten per cent. OF total
phosphoric acid and six and one-half
per cent. OF available phosphoric acid.
BONE MEALS.
There are also three kinds of bone
meal produced: raw gone meal, regu-
lar bone meal, and steamed bone meal.
The first is, as its name indicates.
produced by the crushing and grind
ing Of raw bones. after removing any
adhearing fat or meat. This material
| contains about four per cent. of nitro.
gen, twenty-three per cent. OF total
phosphoric acid. and eight and one
half per cent of available phosphoric
acid. The regular bone meal is cooked
under pressure for few hours in the
tanks; this removes fat and also causes
some loss Of nitrogen, but makes the
product grind easier and finer. This
grade OF bone meal contains about
three per cent. nitrogen, twenty-sevcn
and one-half per cent. total phosphorlc
acid and twelve and one-half per cent.
available phosphorlc acid. Steamed
bone meal Is the product OF the glue
works, and Ia made by grinding the
bones left after boiling all the fat an 4
glue out OF them that can be obtained
This process reduces the percentage
Of nitrogen, so that steamed bone meal
will hardly average more than two
per cent. Of nitrogen, but has about
the same amount of phosphorlc acid
as the ordinary bone meal.
HORN AND HOOP MEAL-MIsccN
CEPTIONS ABOUT.
Horn and hoof meal is another pro.
duct OF the slaughter-house Impe..
feet horns and dark colored hoofs are
first thoroughly steamed, then dried
and ground into meal The better
quality of horn and hoofs command
very high prices. even as high as
5000 a ton, for other purposes, In the
manufacture Of buttons and novelties:
hence the quantity Of this material
coming on the market is limited.
There was formerly great prejudice
against 1t, and II used to be considered
fraudulent to use II in fertilizers.
Even in standard works on Agricul-
tural Chemistry of quite recent date
the material is spoken of as being
very slowly available as plant food
This, however, has In the past two
or three years, been shown to
be an error and the material
Is now regarded by the best in
fornep 90 rich and highly available
source Of nitrogen. ~ - -