12 



HATCH EXPERIMENT STATION. 



[Jan. 



which enter largely into the manufacture of commercial fer- 

 tilizers found in our markets 

 list of such materials : — 



The following is a partial 



Sulfate of ammonia. 

 Nitrate of soda. 

 Azotine. 

 Dried blood. 

 Cotton-seed nrieal. 

 Linseed meal. 

 Bone and tankage. 

 Castor pomace. 

 Dry ground fish. 

 Dry ground meat 



Dissolved bones. 



Acid phosphate. 



Refuse bone-l)lack. 



Ground phosphate rock. 



High-grade sulfate of potash. 



Sulfate of potash and magnesia. 



Muriate of potash. 



Kainit. 



Sylvinite. 



Crude saltpetre. 



As definite instructions have been given from time to time 

 regarding the calculation of the approximate commercial 

 value of fertilizers, no attempt is here made for the discus- 

 sion of that matter. 



Table A, following, gives the average analysis of officially 

 collected fertilizers for 1902 ; Table B gives a compilation 

 of analyses of commercial fertilizers for the year 1902, show- 

 ing the maximum, minimum and average percentages of the 

 different essential elements of plant food in special crop 

 fertilizers, so called. 



