134 
FLORIDA STATE HORTICULTURAL SOCIETY. 
this salt is a by-product of coke and gas 
works. Coal contains from i 1-5 per 
cent to 1 3-5 per cent nitrogen, or from 
24 lbs. to 32 lbs. per ton. Upon reck¬ 
oning the atomic weights of the formula 
2NH4,S04, we find 28 lbs. nitrogen 
makes 132 lbs. sulphate of ammonia. 
When we read that 20 lbs. to 22 lbs. of 
the sulphate is considered a fair yield per 
ton of coal, at either coke or gas works, 
and that comparatively few works try to 
save any at all, we think it would be well 
for some genius to perfect machinery for 
this purpose. 
Nitrate of soda, or properly, nitrate 
of sodium (NaNC>3) shares honors with 
sulphate of ammonia as a source of 
nitrogen for plant food. It is found in 
Chili and like the sulphate and muriate 
of potash from Germany is made by the 
great chemist, Nature, but is as truly 
formed as described as though the nitric 
acid and sodium were mixed with human 
hands. 
Guano is another valuable source of 
plant food, giving us some of all three 
essentials. There are many different de¬ 
posits but in our market we hear only 
of Peruvian guano from the islands off 
the rainless coast of Peru. It is formed 
by sea birds, seals, etc., during life and 
after death. The deposit is often over 
100 feet deep. The lower layers are so 
fossilized as to be “rock guano.” Above 
this have been found seal fur, and some¬ 
times petrified birds’ eggs are taken 
from a depth of from two to twenty-five 
feet. One kind of egg is filled with 
pearly crystals, but you may be sure no 
such curios find their way into a fertiliz¬ 
er sack. Being of such origin the con¬ 
stituents of guano vary greatly and each 
lot must be analyzed. It used to be high 
in ammonia content but now is often 
classed as a phosphatic fertilizer. It con¬ 
tains plant food in many different com¬ 
binations and is especially fitted to some 
lands; but like all good things it has its 
place, so make sure whether your land re¬ 
quires it, for it costs high. And, too, 
make sure you get it when you do buy it. 
I may as well confess right here that, 
thinking it as well for the consumer as 
the manufacturer to be “up-to-date,” I 
subscribe for a magazine published for 
the fertilizer trade. From it I learn 
some points that otherwise I might not 
come across. One thing I noticed was 
the way garbage, leather and wool waste, 
etc., are treated. From them can be and 
is made a very good substitute for gu¬ 
ano when put in a ready mixed fertilizer. 
It is good, and such things should be 
utilized, but it is not guano, and when 
we buy it we do not want to pay for 
guano! So let us be thankful for our 
fertilizer laws and LOOK AT THE 
TAG. 
As we study the sources of phosphoric 
acid, we remember the contents of Farm¬ 
ers’ Institute Bulletin No. 1, and decide 
to skip “dissolved bone,” “boneblack,” 
etc., and learn all we can of plain acid 
phosphate. We find the largest fields of 
the best phosphate here in our own fair 
Florida. From them is shipped 80 per 
cent, of the world’s product. It is sold 
under a guarantee of minimum 77 per 
cent phosphate of lime and maximum 3 
per cent oxides of iron and aluminum. 
This standard is far higher than the Eng¬ 
lish products, yet Griffiths says in his 
“Manures”: “It would be well if the 
prejudice against manures containing 
