110 HATCH EXPERIMENT STATION. [Jan. 



31.22 per cent, phosphoric acid and 51.74 per cent, calcium 

 oxide. His experiments were conducted as follows : 1 part 

 of the apatite was fused with 4 parts of a mixture composed 

 of 23 parts of sodium carbonate and 39 parts of potassium 

 carbonate. The resulting mass was extracted with water, 

 and showed a test of 3.68 per cent, water-soluble phosphoric 

 acid. The residue, u})on treatment with neutral citrate of 

 ammonia, showed a test of 2(3.78 per cent, of reverted phos- 

 phoric acid, leaving only .76 per cent, of phosphoric acid in 

 an insoluble form. In another experiment 1 part of the 

 apatite was fused with 1.15 parts of the same fusing mixture, 

 this amount of sodium and potassium carbonate being theo- 

 retically necessary to convert all of the phosphoric acid into 

 phosphates of soda and potash. The resulting mass showed 

 2.56 per cent, of water-soluble phosphoric acid, 15.96 per 

 cent, of reverted phosphoric acid and 12.70 per cent, of in- 

 soluble phosphoric acid. Mr. Haskins also made experi- 

 ments to ascertain to ^\diat extent the phosphoric acid in 

 apatite would become available if boiled with a solution of 

 sodium and potassium carbonate. Several strengths of 

 solution were used, but only traces of phosphoric acid were 

 dissolved, the residue in no case showing over 1.98 per cent, 

 available })hosphoric acid. From the above observations it 

 will appear that great fields are opened for a more extensive 

 use of our natural phosphates when introduced in a suitable 

 form by some fusing process. 



In conclusion, we must say that the consumption of com- 

 mercial fertilizers is ever on the increase, and it is a great 

 satisfaction to feci that apparently the increased consump- 

 tion of fertilizers is more than off-set by the prospective 

 increase in natural supplies. The increased production of 

 sulfate of ammonia from improved methods in the manufac- 

 ture of coke from bituminous coal, the recent discoveries of 

 new potash deposits in Saxony, Ger., as well as the recent 

 reported discovery of nitrate of soda beds along the Pacific 

 coast in the United States, all furnish pleasant reflections 

 for the future of American agriculture. 



