43 



Sombrero. This is a rock guano, \\hich constitutes the entire 

 structure of one of the windward Islands in the Caribbean Sea. 

 It is somewhat hard, and forms a light yellow powder when 

 ground. It is not near so available for a superphosphate as 

 South Carolina phosphates. Owing to the large amount of 

 oxide of iron, there is a great waste of acid in the manufac- 

 ture ; dangerous compounds are formed, such as copperas and 

 the superphosphate " goes back." 



Navassa Guano. This comes from an Island off the coast of 

 Hayti. It contains a large amount of phosphate of lime, but 

 owing to the abundance of iron and alumina, its conversion 

 into a superphosphate entails a large waste of acid, difficulty 

 of manufacture, and the inevitable " going back " in large 

 quantities. 



Orchilla Guano. This material comes from an island in the 

 Caribbean Sea. It is a damp, fawn colored powder. It is loose 

 in texture, and could be applied directly to the soil, but its low 

 percentage of phosphate of lime renders its money value small, 

 and for conversion into superphosphates, the large amounts of 

 carbonate of lime, iron and alumina, renders it uneconomical. 



There are also on the market the Phcenix Island, Guanahaui, 

 Kedonda, St. Martin's, and other pbosphatic rock guanos, all of 

 which, together with those above named, are inferior in fertili- 

 zing properties to the South Carolina phosphates. 



South Carolina Phosphates. This material comes from the 

 vicinity of the Ashley and other rivers west of Charleston. It 

 is ground without difficulty, and is readily soluble in acids. Of 

 all the mineral phosphates of lime which are available, these 

 are best suited for conversion into superphosphates. 



The mining and manufacture of these has assumed enormous 

 dimensions, some $20,000,000 being invested and the works for 

 the production of superphosphates and manipulated fertilizers 

 are among the most complete and well arranged in the world. 

 The combined capacity of the acid chambers is about 800,000 

 cubic feet: the largest single chamber being that of the Etiwan 

 Company, who convert one hundred tons of sulphur per month 

 into acid. 



They also manufacture the highest grades of superphosphates 

 on the market. 



We here give a table of the analyses of these different Phos- 

 phatic Guanos : 



