FLORIDA STATE HORTICULTURAL SOCIETY. 
93 
about 3 per cent, ammonia and 25 per 
cent, phosphoric acid and on account of 
its fineness is more readily available to 
the plants. The spent bone from the 
sugar refineries is treated with sulphuric 
acid to make its phosphoric acid availa¬ 
ble at once, and is used and sold under the 
name of dissolved bone black. It con¬ 
tains then from 16 to 18 per cent, availa¬ 
ble phosphoric acid. 
Florida phosphates or fossil bone is the 
greatest source of phosphoric acid. This 
is mined in the central and southern parts 
of the State and immense quantities are 
exported to Europe. This phosphoric 
acid in our Florida phosphates is entirely 
insoluble. If it had been soluble it would 
not have remained, but would have been 
dissolved by the soil water and long since 
have disappeared from our country into 
the Gulf of Mexico. Chemistry has come 
to our relief in making this and other 
phosphatic materials available to the 
plant. Sulphuric acid is used in render¬ 
ing water soluble the insoluble phosphor¬ 
ic acid in animal bone and the fossil bone 
in Florida. Each contains phosphoric 
acid and lime combined in the same pro¬ 
portion; one part of phosphoric acid and 
three parts lime which is called bone phos¬ 
phate of lime, which is insoluble. Now 
to make the material, either bone or the 
Florida phosphates soluble and available 
to the plants it is ground and combined 
with sulphuric acid diluted with water to 
52 per cent beaumae. The sulphuric 
acid has more affinity for the lime than 
the phosphoric acid has and combined 
with two parts forming sulphate* of lime 
or land plaster, leaving the phosphoric 
acid combined with one part of lime 
which is soluble in soil water and availa¬ 
ble to the plants. The sulphuric acid 
combining chemically with the lime is no 
more sulphuric acid and there is no more 
danger of your getting free sulphuric 
acid in this preparation than you 
would in sulphate of potash or sul¬ 
phate of ammonia. This idea of 
danger from free sulphuric acid is a 
humbug and not worthy of the slightest 
attention by the intelligent horticultural- 
ists of this State, an idea advanced by a 
northern manufacturer. Soluble phos¬ 
phoric acid is identical no matter from 
what source it is derived, and when some 
growers realize this they will save money. 
One of the northern firms for the last 
twenty years has been trying to make the 
Florida grower believe that all other com¬ 
plete fertilizers have free sulphuric acid 
in them, claiming that through a secret 
process by steaming he makes bone, Peru¬ 
vian guano and other phosphatic mater¬ 
ials all available. This statement has 
been made to many growers in the State 
but would never be made before a fertili¬ 
zer manufacturer or some one who knew 
because the party making this claim 
knows only too well there are no elements 
in water or steam to combine with the 
lime in bone or phosphate to make it 
available even though he should put it 
through a secret isteaming process (for 
seventeen years. 
Peruvian Guano is another fine source 
of phosphoric acid. High grade will give 
9 to 10 per cent, ammonia, 9 to 12 phos¬ 
phoric acid partly available and three to 
four per cent, potash. Lower grades will 
give 3 to 4 per cent, ammonia, 18 to 20 
per cent. Phosphoric Acid and 3 to 4 per 
cent. Potash. All of its phosphoric acid 
sooner or later becomes available in the 
soil. They are not susceptible of treat¬ 
ment with sulphuric acid. 
