242 Report of the Department of Chemistry of the 



millet, crimson clover and vetch. As stated, the applications of 

 P2 5 (3 grams) were uniform throughout. 



The soils used in 189'8-9 were allowed to remain in the boxes 

 until the fall of 1899, when the roots were sifted out and the boxes 

 were replanted after bringing the supply of the important in- 

 gredients up to the following quantities: 



Table III. — Phosphoric Acid Availability Experiments: Fertilizer In- 

 gredients Used, 1899-1900. 



P 2 Os 4 grams — all boxes except " no phosphoric acid " and "blanks." 



N 3.75 " ] 



K 2 7.5 " [■ All boxes except blanks. 



MgS04 + 7H 2 3.75 " J 



Ca SOi -f- 2 H 2 8.4 grams — All boxes not receiving acid phosphate except " blanks." 



Ca CO3, 12.2 grams — All boxes except " no phosphoric acid" and " blanks." 



The second crops on the same soil (quartz sand) were as a 

 rule not successful, only the cabbage and rape making a growth 

 that was considered satisfactory. In January, 1900, the boxes of 

 all crops excepting the cabbage and rape were emptied and re- 

 filled with the same weight of new sand, to which were added 

 smaller amounts of fertilizing materials than in the previous ex- 

 periments. 



These quantities were as follows : 



Table IV. — Phosphoric Acid Availability Experiments: Fertilizer In- 

 gredients Used, 1900. 



P2 Os 1.50 grams. All boxes but "no phosphoric acid" and "blanks." 



N .625 



K 2 1.25 



MgSO, + 7H 2 .50 



Fe,Cl. .375 " 



CaSOi-f 2 H 2 3.00 " 



Ca COa 5.00 " All boxes but "no phosphoric acid" and "blanks." 



u 

 It 



All boxes but blanks. 



In all, then, a record has been made of the growth on different 

 phosphates of three crops of several species of plants. It is 

 believed that logical conclusions can be drawn from the data 

 thus secured, conclusions that are in the main harmonious with 

 the outcome of previous experiments along the same line. 



Results of experiments with different phosphates on a poor 

 natural soil from pine plains near Geneva. — For reasons that 

 will appear later, a record was made simply of the air-dry crops 

 grown in the 1896-7 experiments. The weights of the crops on 



