78 



On the Inorganic Constituents of Plants, 



Ammonia were not quite so rank, whilst those manured with Phos- 

 phate of Ammonia and Nitrate of Soda, though as large and 

 flourishing as those treated with Muriate of Ammonia, were not 

 quite so dark in colour. Next in size and appearance were the 

 plants manured with Sulphate of Potash, then those manured with 

 Sulphate of Lime and Sulphate of Magnesia. The Muriate of 

 Potash appeared to exert but little influence until the wheat came 

 into ear. The other salts did not in any material way affect the 

 appearance of the wheat. A slight beneficial effect was throughout 

 produced by the Silicate of Potash, each square to which it had 

 been applied, in conjunction with a saline manure, looked better 

 than the corresponding square to which the Silicate had not been 

 applied. 



The crops were attentively watched from time to time to ascertain 

 whether any of them were more liable to blight or diseases than the 

 others, but no such effect was observed, a few smutty ears were 

 found in most of the squares, and in a few places red rust appeared, 

 but it did not seem that there was any connexion between those 

 diseases and the manures employed. 



A number of grains of wheat selected from each square, was sown 

 in similar soil, and exposed to the same circumstances, to ascertain 

 whether there was any difference in the time required for germina- 

 tion. In the first trial, considerable differences appeared to exist in 

 the rapidity of germination ; the seeds from those squares which 

 had been manured with Silicate of Potash, all came up first ; this 

 was however probably due to some accidental circumstance, for on 

 repeating the experiment with greater care no appreciable differ- 

 ence was perceptible. 



For the convenience of reference some of the numerical results 

 of the preceding experiment are arranged in the following tables. 



