5ft now cRopfi PEEn. 



tural plants to tlic production of tlie albuniinokls.* We 

 measure the nutritive efFoct of aminonia salts applied as 

 fertilizers by tlie amount of nitrogen whicli vegetation as- 

 similates from them. 



Effects of Ammonia on Vegetation. — The remarkable 

 effect of carbonate of ammonia upon vegetation is well 

 described by Ville. We know that most plants at a cer- 

 tain period of growth under ordinary circumstances cease 

 to produce new branches and foliage, or to expand those 

 already formed, and begin a new phase of development in 

 providing for the perpetuation of the species by producing 

 flowers and fruit. If, however, such plants are exposed 

 to as much carbonate of ammonia gas as they are capable 

 of enduring, at the time when flowers are beginning to 

 form, these are often totally checked, and the activity of 

 growth is transferred to stems and leaves, Avhich assume 

 a new vigor and multiply with extraordinary luxuriance. 

 If flowers are formed, they are sterile, and yield no seed. 



Another noticeable effect of ammonia — one, however, 

 which it shares with other substances — is its power of deep- 

 ening the color of the foliage of plants. This is an indi- 

 cation of increased vegetative activity and health, as a 

 pale or yellow tint belongs to a sickly or ill-fed growth. 



A third result is that not only the mass of vegetation 

 is increased, but the relative proportion of nitrogen in it is 

 heightened. This result was obtained in the experiment of 

 Peters and Sachs just described. To adduce a single other 

 instance, Ville found that grains of wheat, grown in pure 

 air, contained 2.09 per cent of nitrogen, while those which 

 were produced under the influence of ammonia contained 

 3.40 per cent. 



* In tobacco, to th3 prodaction of nicotine ; in coffee, of caffeine ; and in many 

 other plants to analogous eubstances. Plants appear oflentiraes to contain 

 small quantities of ammonia salts and nitrates, as well as of asparagin, (C4 Hs 

 N2 03,)a substance first found in asjjaragus, and which is formed in manj 

 plants when they vegetate in exclusion of light. 



