FLORIDA STATE HORTICULTURAL SOCIETY. 
115 
ammonia in almost every section where 
fertilizer is used. The blood is run 
through presses which extract a large 
amount of the moisture and the residue 
is put through a drier and screened. The 
value of the blood depends on how care¬ 
fully the separation of other materials 
is made in the slaughter houses. Dried 
blood frequently analyzes as high as 17.75 
per cent, ammonia and it’s not unfre- 
quently as low as 14 per cent. Dried blood 
is one'of the best sources of animal am- 
moniates and is considered by chemists 
and agriculturists to be first on the list 
of value as an animal ammoniate. 
BLOOD AND BONE. 
The name blood and bone is familiar 
to the users of fertilizers but to the man¬ 
ufacturers and trade the name is tankage. 
All blood and bone is tankage but all 
tankage is not blood and bone. In the 
slaughter houses every scrap of meat, 
bone and blood that cannot be used for 
some other purpose is gathered together 
and put into a large tank and cooked. 
The cooking process is continued for 
some time or until all the matter is so 
broken up that the grease will float on 
top. The grease is then drawn off and 
the residue dumped into large hydraulic 
presses and the water squeezed out and 
the remaining material run through a 
drier, ground and screened. Then we 
have tankage or blood and bone. 
The value of the blood and bone de¬ 
pends of course on what goes into the 
tank. The more bone that goes into it 
the higher in phosphoric acid and the 
lower in ammonia and vice versa. The 
many uses to which bones can be put out¬ 
side of the use for fertilizer has made & 
valuable market for same consequently 
but a small proportion of the bone pro¬ 
duced at the slaughter houses goes into 
the fertilizer and the tankage now pro¬ 
duced usually runs high in ammonia and 
low phosphoric acid. The rnost popular 
kind on the market now is what is known 
as 10 and 10 tankage, that is 10 per cent, 
ammonia and 10 per cent bone phosphate 
of lime. 
The small slaughter houses, however, 
do not as a rule produce as high grade 
tankage because they do not have ma¬ 
terials enough to warrant close separa¬ 
tion, consequently their tankage contains 
more bone and less ammonia, usually 
running 6 to 61-2 per cent, ammonia and 
25 to 30 per cent, bone phosphate of 
lime. 
When the slaughter house managers 
found an outlet for their waste material 
they thought their troubles were at an 
end, but the enormous amount of water 
that was pressed out of the tankage found 
its way into the city sewers and polluted 
the streams, which soon called for a 
change. This was brought about bv put¬ 
ting in large evaporators and evaporating 
the water that comes from the presses. 
When this water is evaporated it leaves 
a thick substance in the pans which is al¬ 
most equal to dried blood in its value as 
an ammoniate. It has a very objection¬ 
able quality, however in not being “con¬ 
sistent.” It will not remain in a me¬ 
chanical condition any length of time 
after it is made up, without the addition 
of foreign material. From its stick na¬ 
ture and tendency to dissolve and become 
solid it has been called “Stick” or con¬ 
centrated tankage. In recent years, how¬ 
ever, methods have been discovered for 
handling this concentrated tankage so it 
is added to the other tankage and remains 
in a good mechanical condition and makes 
in every way a very desirable source of 
animal ammoniate. 
