The above schedule of trade values for 1907 was adopted by repre- 

 sentatives of the Massachusetts, Connecticut, Rhode Island, Maine, 

 Vermont and New Jersey Experiment Stations at a conference held 

 during the month of March, 1907, and is based upon the condition of 

 the fertilizer market in centers of distribution in New England, New 

 York and New Jersey during the six months preceding March, 1907, 

 and refers to the current market prices, in ton lots, of the leading 

 standard raw materials, which furnish nitrogen, phosphoric acid and 

 potash, and which enter largely into the manufacture of our commer- 

 cial fertilizers. The following is a list of such materials : 



Sulphate of ammonia, Ground phosphate rock, 



Nitrate of soda, Acid phosphate, 



Dried blood, Refuse bone black. 



Cotton seed meal. Carbonate of potash. 



Castor pomace. High grade sulphate of potash. 



Linseed meal, ^ Muriate of potash, 



Dry ground fish, Sulphate of potash-magnesia, 



Bone and tankage, Kainit, 



Crude saltpetre, Sylvinite. 



Dissolved bone, 



A comparison of the trade values of the essential elements of 

 plant food for 1907, with the previous season, shows nitrogen in the 

 form of nitrates two cents higher in cost than during the season of 

 1906. The different forms of organic nitrogen show an increase 

 in cost over that of the previous season of from two to two and 

 one-half cents per pound. 



Both the water soluble phosphoric acid and the citrate soluble 

 (reverted) phosphoric acid show an increased cost of one-half cent 

 per pound over that for 1906. 



The cost of the various forms of potash remains the same as for 

 the previous year. 



Valuation. The approximate value of a compound fertilizer or 

 any material used for fertilizing purposes is obtained by calculating 

 the value of each of the three essential elements of plant food (nitro- 

 gen, phosphoric acid and potassium oxide, including the dififerent 

 forms of each wherever different forms are recognized in the table) 

 in one hundred pounds of the fertilizer, and multiplying each product 



