editor's preface. V 



forming a double flower arise from the transformation of the 

 filaments of the stamens into petals, and that petals are 

 merely advanced forms of leaves. Ammonia, then, per- 

 forms the action of increasing the surface of the foliar ap- 

 pendages, or the leaves of plants ; that it also increases the 

 health of these parts may be seen by the bright, deep green 

 and luxuriant growth of plants manured by nitrate of soda, 

 or Chili saltpetre, and by those in pots watered with a solu- 

 tion of guano. In trees this action extends to shoots and 

 branches. 



As the absorption of a considerable portion of the nour- 

 ishment of plants, and the rejection of nearly all the useless 

 parts thrown off by them, are actions of the leaves, it is evi- 

 dent that a luxuriant and healthy state of these organs must 

 essentially conduce to the vigorous action of all the other 

 functions, and chiefly to that one so important to the agri- 

 culturist, the bearing of seed. But besides the nitrogenous 

 portions of the seed, one other ingredient here is absolute- 

 ly necessary, namely, phosphoric acid, or the phosphates 

 (salts of phosphoric acid) ; without these, all the ammoni- 

 acal manure in the world would fail to give crops of grain ; 

 both of these in abundance, on properly tilled soil, will give 

 the heaviest possible harvests. Nor is this all ; for the lux- 

 uriance and vigor induced by ammonia will enable the plants 

 to absorb and use up more than the usual quantity of the 

 phosphates, and the grain will naturally be richer in these 

 ingredients. Now as all flesh, blood, and bone require a 



