HISTORY OF THE AMERICAN MENHADEN". 227 



would act as a preservative, and further, the potash supplies a lack in 

 the fish and makes of it a " complete " fertilizer. 



The amounts of the " acidulated " fish and "fish and potash salts " in 

 the market are so small as to give them very little importance. 



Manufacture of '■'■ ammoniated superpliospliatesy 



297. The most important use of fish waste is in the manufacture of 

 nitrogenous, *' ammoniated," superphospates. These fertilizers, which 

 constitute by far the largest class in the market, owe their value mainly 

 to the two ingredients, nitrogen and phosphoric acid. For phosphoric 

 acid various fossil and mineral phosphates, particularly those from South 

 Carolina and the Island of J!:Tavassa, are employed. Of late, mines of 

 apatite have been opened in Canada, and promise to be a rich and im- 

 portant source of phosphates for this purpose. The waste boneblack 

 from sugar refineries is also used in very large quantities for the same 

 purpose. Bono meal is likewise employed, but to a limited extent. The 

 phosphoric acid in all of these is in insoluble or very slowly soluble 

 forms. To render it more available, the pbosphates are treated with 

 sulphuric acid, and thus superphosphates are produced. 



Various materials are used to supply nitrogen (ammonia) to super- 

 phosphates. Dried blood and meat-scrap from slaughter-houses are, 

 next to fish, the most important materials in common use for this pur- 

 pose. Formerly a good deal Peruvian guano was employed. In Europe 

 considerable suli)hate of ammonia is used, but manufacturers there are 

 learning that they can get nitrogen cheaper in American fish and slaugh- 

 ter-house products, and thousands of tons of our best nitrogenous 

 materials are annually taken from us and sent across the Atlantic to 

 enrich English, French, and German soils. 



According to the report of Mr. Haddocks, already referred to, " nine- 

 tenths of the fish scrap turned out at the works of the Maine associa- 

 tion are bought by the manufacturers of superphosphate to ammouiate 

 their products, of which 400,000 tons are produced yearly in the United 

 States. They combine it, when dried and pulverized, with South Car- 

 olina phosphatic rock, ground bones, with imported guano deficient in 

 ammonia, «S:c. It is understood that not over one ton of the fish guano 

 is used in connection with three or four tons of the mineral ingredients." 



The largest manufacturers of superphosphates in this country are 

 the Pacific Guano Company, whose works are at Wood's Holl, Mass., 

 and near Charleston, S. C. This company use fish and the Charleston 

 phosphate for the manufacture of their superphosphate, the " Soluble 

 Pacific Guano." The Quinnipiac Fertilizer Company, of New Haven, 

 Conn., whose works are on Pine Island, near New London, Conn., and 

 the Cumberland Bone Company, of Boothbay, Maine, are, with the 

 Pacific Guano Company, the best representatives of this most useful 

 industry. The detailed descriptions of their factories and methods of 

 manufacture, prepared by Mr. Gootle, are at once too extensive to be 



