EXrERDIENTS WITH SALTS OF AMMONIA. 



297 



mouia was inoperative or weaker, tliis experiment would 

 be amply sufficient to confute the notion which had 

 been attached to nitrogen. For if this notion was cor- 

 rect, the ammonia ought to operate in all cases in which 

 the guano operated, and exactly in the same manner. 

 The oldest experiments in this direction were made by 

 Schattenmann ('Compt. rend.' t. xvii.). 



He manured ten plots of a large wheat-field with sal 

 ammoniac and sulphate of ammonia; an equally large 

 plot remained unmanured. Of the manured plots, one 

 received 162 kilogrammes ( = 3561bs. Eng.) per acre; the 

 others received the double, treble, and quadruple quantity 

 of each of these salts. 



The salts of ammonia (says Schattenmann, p. 1130) 

 appear to exert a remarkable influence upon wheat ; for, 

 only eight days after manuring, tlie plant assumed a deep 

 dark-green colom% the sure sign of high vegetative power. 



The returns obtained by manuring with the salts of 

 ammonia were the followinij^ : — 



Muriate of ammonia employed 



(1) 1 acre 



(2) 1 „ 



(3) 4 „ 



Average of the four 

 Sulphate of ammonia emploj'ed 



kilo. 



acre . 162 



» • 324 



486 

 Average of the four 



kUo, 

 324 

 486 



kilo. cwt. 

 1182 = 23 

 1138 = 22 



1174 = 23 

 903 = 18 



kilo. cwt. 

 2867 = 56 

 3217 = 63 



3171=62 



3078 = 60 

 .1248=63 



kilo. cwt. 

 44=0-8 



kilo. cwt. 

 348=6-8 



211=4-0 

 381 = 7-5 



It is easy to see that the expectations which had been 

 founded u})on the deep dark-green colour were not 



