CHEMISTRY OF FERTILIZERS 3 



new branches and foliage, or to increase those 

 already formed, and commence to produce flowers 

 and fruits, whereby the species may be perpet- 

 uated. If a plant is provided with as much 

 available nitrogen as it can use just at the time 

 it begins to flower, the formation of flowers may 

 be checked, while the activity of growth is trans- 

 ferred back to and renewed in stems and leaves, 

 which take on a new vigor and multiply with 

 luxuriance. Should flowers be produced under 

 these circumstances, they are often sterile and 

 produce no seed. 



The next effect of nitrogen upon plants is 

 to deepen the color of the foliage, which is a 

 sign of increased vegetative activity and health. 

 Another effect of nitrogen is to increase in a 

 very marked degree the relative proportion of 

 nitrogen in the plant. 



Potash is essential to the formation and trans- 

 ference of starch in plants. Starch is known 

 to be first formed in the leaves of plants, after 

 which in some unknown way it becomes soluble 

 enough within the plant cells to enable it to pass 

 through the cell-walls gradually and later to 

 be carried into the fruit, where it accumulates 

 and changes back to its insoluble form. It is 

 well established that potash is intimately con- 

 nected with the formation of starch in the leaves 

 and with its transference to the fruit. No other 

 element can take the place of potash in perform- 

 ing this work. Potash is important on account 



