318 SALT, NITRATE OF SODA SALTS OF AMMONIA ETC. 



Bogenhausen, 1858 (p. 287). 



In both these series of experiments, the crops of 

 corn and straw were remarkably increased by the addi- 

 tion of common salt ; and it is scarcely necessary to 

 repeat, that such an augmentation could not possibly 

 have taken place unless the soil had contained a certain 

 quantity of phosphoric acid, silicic acid, potash, &c., 

 capable of being brought into operation, but which 

 without common salt was not assimilable. 



Similar experiments were undertaken by the same 

 society in Weihenstephan with nitrates ; and the crops 

 produced by these salts alone, and with the addition of 

 common salt, per hectare, were as follows : 



Weihenstephan, 1857. Summer barley. 



The experiments are remarkable in so far as they 

 appear to indicate the cases in which the nitrates alone, 



