54 FERTILIZERS. 



product had come to town, the driver stopped, when 

 abreast the house, and told me he had a ton of horn- 

 waste bearing my address. I got rid of the elephant the 

 easiest way possible, by tumbling it into the manure cellar, 

 and throwing the daily manure upon it until it disap- 

 peared from view. My men found combs, more or less 

 perfect, among the mass, enough to supply their families 

 for a year or more. This stuff is very rich in ammonia ; 

 but, though by layering it with horse manure it might be 

 softened and dissolved by fermentation, yet it is so bulky 

 that even at a low figure few farmers would care to invest 

 in it. 



PHOSPHORIC ACID. 



This, the third substance in the three components of a 

 complete fertilizer, is composed of the element phosphorus 

 combined with the gas oxygen. The four great resources 

 for phosphoric acid are the mineral called apatite, which 

 contains ninety-two per cent of phosphate of lime, and is 

 believed by some scientists to be the original source in 

 nature from which phosphate of lime is derived ; the 

 phosphatic guanos, which are the dung of sea-fowls from 

 which the ammonia has been washed out by the rain; the 

 bones of all animals; and the mineral phosphate rocks, 

 which are the remains of ancient marine animals. Min- 

 eral phosphates have within a few years been discovered 

 to exist, in almost limitless extent, in North and South 

 Carolina and Georgia, usually accompanying beds of marl, 

 either just above or just below them, and covering hun- 

 dreds of square miles^ They exist largely as nodules of 

 rock, having holes or depressions on their surface filled with 

 worthless material, which makes it necessary to wash them 

 before grinding. That they are marine remains is evident 

 to the eye from their composition, which includes marine 

 shells and numberless sharks' teeth, some being in a per- 



