126 Experiment Station Report. 



are the regular source of supply. They also correspond to 

 the average wholesale quotations. 



The calculated values obtained by the use of the above 

 figures will be found to agree with the reasonable retail 

 price in case of standard raw materials, such as, — 



Sulphate of Ammonia, Azotin, 



Nitrate of Soda, Dry Ground Fish, 



Muriate of Potash, Cotton Seed, 



Sulphate of Potash, Castor Pomace, 



Dried Blood, Bones, 

 Plain Superphosphates. 



The particular rate of valuation of each ingredient used 

 for manurial purposes depends, in many instances, largely 

 on its mechanical condition and its peculiar form of com- 

 bination. For instance, in factory- waste, and animal and 

 vegetable refuse of various descriptions. 



It has been the aim in previous reports of the station to 

 describe briefly, in connection with analytical reports re- 

 garding their composition, the peculiar character and special 

 merits of prominent agricultural chemicals, and of refuse 

 materials of various industries which are commonly used for 

 the manufacture of compound fertilizers for farm purposes. 



This feature of the reports will be retained for the future 

 wherever an inducement is ofiered. The information thus 

 far given on these occasions may be improved by studying 

 the official annual reports on commercial fertilizers pub- 

 lished for ten years past in the report of the Massachusetts 

 State Board of A2:riculture. A knowled2:e of the sources 

 and of the character of the ingredients which serve largely 

 for the manufacture of our commercial fertilizers, leads 

 quite naturally to a due appreciation of the importance of 

 securing the proper form for our circumstances. No mode 

 of supplying our special wants of plant food for a successful 

 and economical cultivation of crops is as safe as the practice 

 to supplement, if needed, our home-made manures with 

 commercial fertilizing ingredients, in the form of suitable 

 raw materials and chemicals to meet our wants ; and if 

 obliged to increase our home resources of manure, to com- 

 pound them from the most suitable stock in the market. 

 Although a first trial of that course of action may not realize 



