Gypsdm. 

 Moisture at 100° C, 

 Calcium oxide, 

 Sulphuric acid, 

 Insoluble matter, 



LIME. 



Calcium oxide, 

 Insoluble matter, 



It will be seen that the ascertained composition was found to be so 

 near the proposed that the amounts of nitrogen, phosphoric acid and 

 potash supplied per acre were not essentially different from the 

 amounts fixed upon in the convention as appropriate. The exact 

 figures per acre are as follows : Nitrogen, 24 pounds ; available phos- 

 phoric acid, 69.2 pounds ; and potash, 72.3 pounds. 



In all cases fertilizers and manures were evenly spread broadcast 

 upon the ploughed land and harrowed in just previous to planting 

 the seed. 



5. The selection of seed was left to the individual experimenters, 

 as it was felt that success would be more certain with varieties suited 

 to the several localities and familiar to the cultivators. In every case 

 a variety of yellow flint corn was selected. The rows were in all 

 cases three and a half feet apart and hill planting was generally 

 adopted. 



6. Pvach experimenter was furnished with a standard maximum 

 and minimum thermometer and a lain gauge ; and, although acciden- 

 tal breakages of instruments caused some irregularities, observations 

 were generally kept up from about the middle of June to the time of 

 harvest. A summary of the record of each observer will be found 

 under the account of his experiment. 



7. Each experiment was visited once by myself during July and 

 once by Mr. Cooley during August, and the latter gentleman assisted 

 in the harvest, weighed the crops on the several plots and took a 

 sample from each in every experiment. 



These samples will be analyzed as rapidly as our resources permit 

 and the results, if deemed of sufficient importance, will be hereafter 

 published. 



8. A large number of systematic measurements were taken by 

 several of the experimenters. These were advised with a view to a 

 study of the effects of the several fertilizers during different stages 

 of the growth of the crop. The general method of measurement was 



2 



