ARTIFICIAL MANURE. 187 



Lowell, no less distinguished for the good sense with 

 which he undertakes an experiment, than for the 

 public spirit which urges him onward to its success- 

 ful conclusion. On the principles which have been 

 developed, when saltpetre is used, the whole alkali 

 is let loose by the action of the growing plant. 

 The experience of Mr. Whipple, is a guide to the 

 quantity of alkali which may be safely used. He 

 has used from 50 to 150 lbs. of saltpetre per acre. 

 The real alkali in saltpetre, may be called 1-2 of its 

 weight ; or the real alkali used, has been from 25 to 

 751bs.=36 1-2 lbs. and 109 1-2 lbs. pure carbon- 

 ate, or in round numbers, an average of commercial 

 1st and 2d quality, of 49 to 149 lbs. per acre — giv- 

 ing an average of 99 lbs., which is nearly 1 percent, 

 of the weight of a cord of green peat, which agrees 

 with the estimate (268). If then, this is mixed 

 with the usual proportion of geine, which the dung 

 used contains, equally good effects per acre ought to 

 be produced. 



270. There are other practical facts, which may 

 help to a solution of the question, how much alkali 

 is to be added to a cord of peat. According to the 

 experience of Mr. Phinney of Lexington, an author- 

 ity which may not be questioned, a cord of green 

 dung converts twice its bulk of peat, into a manure, 



