84 CHARLES ANTHONY GOESSMANN 



was omitted in order to get the residual effect, while 

 the supply of nitrogen and potash was increased one- 

 half. 



The crops and yields in the several years were as 

 follows in pounds: 



TOTAL PHOSPHORIC ACID ADDED AND REMOVED 



1890-1896 



As a result of these observations Goessmann con- 

 cluded that for the first two years the dissolved bone- 

 black led, while afterwards the insoluble phosphates 

 were ahead in the following order: basic slag, South 

 Carolina phosphate, and Mona guano. 



