The Analysts of Fkrtiijzers. 283 



of South Carolina are especially abundant along the rivers 

 whidi empty their waters into the Charleston Harbor. On 

 our borders supplies come from the Province of Onta- 

 rio, Canada, while several of the smaller islands of the 

 West Indies are peculiarly rich in phosphatic rock. Britain 

 has been working away for years on her deposits of copro- 

 lites and now as estimated raises 200,000 tons annually. 

 Phosphorites are abundant in Spain, France, Germany, and 

 especially in Russia. 



From these sources is derived the raw material that is 

 wrought up into phosphatic fertilizers. 



Nttrogen Compounds. — The sources of the compounds 

 of nitrogen used for agricultural purposes are more various 

 than those of potassium or phosphorus. 



At the head of the nitrogenous fertilizers stands Peruvian 

 guano, the partially decomposed exuvia of sea birds ; valua- 

 ble not only for its content of nitrogen l>ut furnishing as 

 well phosphoric acid and potash, the former in considerable 

 the latter in small quantities. Soda, saltpetre from Chili or 

 Peru, ammonia salts produced from the destructive distilla- 

 tion of bituminous coal and organic matters, bone meal, 

 fish scraps, and slaughterhouse refuse, are other materials 

 used in the preparation of nitrogenous fertilizers. 



These substances named above containing compounds of 

 potassium, phosphorus or nitrogen or all of these, some 

 used without, but more with previous chemical prepara- 

 tion have been crowdini; themselves into the notice of con- 

 servative farmers in Britain and Germany, and have estab- 

 lished a reputation for restoring the impaired or lost fertil- 

 ity of their fields. 



