The Marietta journal. [volume] (Marietta, Ga.) 1866-1909, 1905-01-12

cakes; these cakes are next broken up
and dried BY passing them through a
mechanical drier heated by steam
The damp cakes go in at one end of
the machine and dry cakes come out
at the other, when they are ground
to powder and sacked ready for mar
ket. This blood will usually contain
about thirteen per cent. of nitrogen.
which, is the equivalent of about six
teen per cent. of ammonia. but as in
the case of the cottonseed-meal, there
is actually no ammonia in It.
Tankage.
The next important product of the
slaughter-house is what is known to
the fertilizer trade at "Tankage." This
is mixture of blood. bones, waste
scraps of meat, etc. This material
gets its name from the fact that 1t is
cooked in huge tanks in the first stage
of its preparation. 1t is cooked un.
der steam pressure at a high tempera.
ture for several hours. AS a result.
most Of the fat in the mass Is melted
and rises to the top of the tanks, where
it is skinned off and utilized for soap.
making and other purposes. The
bones and the cooked meat, etc, now
lie at the bottom of the tank, and the
tank water Is dark and highly colored
lis in fact sort Of soup, containing
heterogeneous matter in solution. The
solid matter, bones etc, are removed,
dried and crushed or ground in thu
same way as was done with the dried
blood product.
Bone Meal.
There are also three kinds OF bona
meal produced: raw bone meal, reg.
ular bone meal, and steamed bono
meal The first is, as its name indi.
Gates. produced by the crushing and
grinding of raw bones, after remov.
ing any adhering fat or meat This
material contains about four per cent,
Of nitrogen, twenty-three per cent. OF
total phosphoric acid, and eight and
one-half per cent. of available phos
phoric acid. The regular bone meal
Is cooked under pressure for a few
hours in the tanks; this removes fat
and also causes some loss of nitrogen,
make the product grind easier and
finer This grade of bone meal con.
tains about three per cent. nitrogen
twenty-seven and one-half per cent.
total phosphorIc acid twelve and one.
half per cent. available phosphorus
acid Steamed bone-meal is the prod
uct of the glue works, and is made
by grinding the bone left after boiling
all the fat and 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
phosphoic acid as the ordinary bone
meal.
Horn and Hoof Meal, Misconceptions
About.
Horn and hoof meal is another prod.
uct of the slaughter house. Imper.
feet horns and dark-colored hoofs are
first thoroughly steamed, then dried
and ground into meal. The better
quality of horns and hoofs command
very high prices, even as 5000 a ton.
for other purposes, in the manufacs
ture OF buttons and novelties; hence
the quantity of this material coming
on the market Is limited. There was
formerly a great prejudice against It.
and 1t used to be considered fraudulent
to use 1t In fertilizers. Even In stand.
ard works on agricultural chemistry
of quite recent date the material is
spoken OF as being only very slowly
available as plant-food. This, how.
ever, has in the past two or three
years been shown to be an error, and
the material is now regarded by those
best informed as a rich and highly
available source OF nitrogen. 1t con.
tains about fifteen per cent. of nitro
gen. The quantity of 1t on the market
is comparatively small. There ars
many other products of the packing.
house, but these are the chief ones of
interest to the fertilizer trade, and to
the farmer
In the next letter I will finish de-
scribing the heterogeneous fertilizer ma.
terials. and write you something about
phosphates.
Yours truly,
VnITAy NJ NrrDY