28 CHEMICAL FERTILIZERS 



phosphates may be graded up so as to produce an article 

 with a percentage sufficiently high to justify carriage. 



English Sources. The English sources are mostly 

 worked out. Various coprolites in Cambridge, Suffolk, 

 and Somerset contain from 50 % to 60 % of phosphate and 

 from 2 % to 30 % of calcium carbonate. These deposits 

 are very largely concretions, and are now little utilized, 

 owing to the competition of foreign phosphates. Some of 

 these phosphates are fossil bones of animals living in pre- 

 historic times. 



Canadian Sources. Deposits of apatite in Ontario and 

 Quebec have been worked for a long time, but have now been 

 given up, as the costs of production were almost prohibitive, 

 owing to the high costs of labour and transport. These 

 apatites contain fluorine equal to 6 % or 7 % calcium fluoride. 



Oceania. Many of the islands in Oceania and the 

 Pacific possess deposits of guano, some of which have been 

 washed out by rain to such an extent that there is little 

 organic matter or nitrogen left, while the phosphates have 

 been concentrated up to 80 %. In addition to these, there 

 are in New Zealand deposits of phosphatized limestone, 

 containing 50 % phosphate of lime, which can be excavated 

 like gravel. Christmas Island, south of Java, yields a 

 phosphate of about 80 % strength, which is very suitable for 

 superphosphate manufacture. 



United States of America. Many deposits of phos- 

 phates in the United States have been discovered and worked 

 with characteristic energy. Some of the best known of 

 these are the Florida phosphates, which consist either of 

 hard rock phosphates, containing 80 % calcium phosphate, 

 or soft clay phosphates, containing about 40 % to 60 % 

 calcium phosphate. Phosphates from the Peace and Alabama 

 rivers are obtained largely by dredging. Tennessee contri- 

 butes some phosphates which are mostly discovered in veins 

 or pockets ; they are easily obtained without much labour 

 or washing as 'a grade of 60 % to 70 % phosphates. Of 

 somewhat less importance are the deposits in Carolina, which 

 extend from North Carolina into South Carolina, forming 



