The original source of phosphoric acid as a fertilizer
was animal bone, just as hard-wood, unleached ashes were the source of
potash. The organic character of the animal bone made it appear more
truly a manure than could any rock or other inorganic substance. There
is no more satisfactory source of phosphoric acid than animal bone, and
if it were in full supply for the needs of soils, there would be little
occasion to discuss the merits of rock-phosphate and other similar
materials. The supply is a small fraction of the need. If all animal
bone were carefully saved and returned to the land that produced all of
our animals, it would return to the soil only what those animals
carried away in their bones, and that is indeed a small fraction of all
the draft our crops make upon the soil's supply of this one substance.
Some of the best animal bone goes into the manufacture of articles that
never contribute anything to the soil, and there are other sources of
loss. The supply of phosphoric acid from bone is too small, when
compared with the land's need, to deserve more than a small fraction of
the consideration it receives by users of commercial fertilizers.
The peculiar situation respecting animal bone has come about through a
form of deceit. The demand for bone existed, and there was no legal
restraint in the matter of branding phosphatic rock as "bone,"
"bone-phosphate," etc. In the past, nearly all forms of rock-phosphates
have carried the word "bone" on the bag to quiet the apprehension of
those who entertained a prejudice against anything other than animal
bone. Nearly all the phosphoric acid has come from rock, and its use
has been necessary and profitable, but the misrepresentation fostered
the old-time prejudice. Within recent years some manufacturers have
tired of the seeming deceit that served no purpose with many customers,
and have placed acid phosphate and mixed goods upon the market without
the intimation that the phosphoric acid was derived from animal bone.
The demand for bone makes prices high for the very limited amount upon
the market, when availability is taken into account, and the advice
that such goods be used would be valueless if it had any general
acceptance. Prices would go higher, and the amount in the world would
remain wholly inadequate.
Next: Raw Bone