12 



HATCH EXPERIMENT STATION. [Jan. 



which enter largely into the manufacture of commercial fer- 

 tilizers found in our markets. The following is a partial 

 list of such materials : — 



Sulfate of ammonia. 

 Nitrate of soda. 

 Azotine. 

 Dried blood. 

 Cotton-seed meal. 

 Linseed meal. 

 Bone and tankage. 

 Castor pomace. 

 Dry ground fish. 

 Dry ground meat. 



Dissolved bones. 



Acid pliosphate. 



Refuse bone-ljlack. 



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 maxinumi, minimum and average percentages of the 

 different essential elements of plant food in special crop 

 fei-tilizers, so called. 



