41 



twenty inches high ; Nos. 5 and 6, rich old lands, new grounds 

 and bottom lands. The first line in the table shows the maxi- 

 mum amount of Dissolved Bone of twenty-four per cent, solu- 

 bility recommended for an acre ; the second line the amount of 

 cotton seed for same ; the third line the amount of phosphoric 

 acid, in pounds, supplied by 150 pounds Dissolved Bone, twenty- 

 four per cent.; the fourth line the amount of sulphate of lime, 

 or land plaster, supplied by 150 pounds Dissolved Bone; the fifth 

 line the amount, in pounds, of ammonia, approximately, sup- 

 plied by number of pounds of cotton seed above, in same col- 

 umn ; the sixth line the amount of potash in pounds, approxi- 

 mately, supplied by the cotton seed in column above. 



Lands of the classes five and,, six will make crops without 

 ammonia, and generally, except when sandy, have a sufficient 

 supply of potash. Of course the farmer may vary this formula, 

 and may substitute stable manure, in whole or in part, for cot- 

 ton seed. 



In the sand region, or on porous soils, it will be best to use 

 Dissolved Bone and potash combined. This can be readily ob- 

 tained by purchasing the Etiwan Chemical Crop Food. 



It may not be amiss for me to add that strong stable manure 

 and cotton seed are about equal to each other in value, so far 

 as ammonia is concerned. 



CHAPTER VII. 

 COMMERCIAL FERTILIZERS, 



The raw materials used in the manufacture of commercial 

 fertilizers are the different Phosphates of Lime, Ammoniacal 

 matters, Salts of Potash, Sulphuric Acid, and Nitrate of Soda. 



The sources of the chief class, that is the phosphates, are all 

 natural, being bone black, ashes, apatite, phosphorite, coprolites, 

 and the various " marl stones" and " rock guanos." 



Bone Black. This material, also known as animal charcoal, 

 is made by calcining or burning raw bones in a closed retort, so 

 as to drive off all volatile matter except carbon and phosphate 

 of lime. This residue, when ground, is sold to sugar refineries 

 for decolorizing their solutions. After having been used and 

 " revived " several times, its bleaching power is exhausted, and 

 it is then sold either as a manure itself or to the manufacturer 

 of superphosphates. 



Bone Ash is a greyish white powder, obtained by calcining or 

 burning raw bones in an open vessel, so that by the free ac- 

 cess of oxygen all the carbon, organic matter and moisture is 

 driven off, and but the mineral matter remains. This is composed 



