the roots. A small quantity does a great amount 

 of good, while the use of large quantities is 

 harmful. The yield of the crop will be limited 

 only by the quantity of nitrates the plant can 

 assimilate. It is of special use for forcing, and 

 the rapid development of vines and young 

 plants. It does its best work in one season 

 with quick results and large returns. It will 

 sweeten sour land. Nitrate of soda is supposed 

 to have been formed by the gradual decomposi- 

 tion of the manures of large and small marine 

 animals and vegetable matter. 



NITRATE OF SODA 



Is found in Chili. The beds of nitrate 

 are several thousand feet above the sea 

 in a rainless region on a desert plain. The 

 deposit is about twenty miles wide and seven- 

 ty-five long. The surface of the bed is cov- 

 ered with earth and rock called costra. This 

 varies in thickness from three to ten feet. It 

 is blasted and removed to uncover the caliche 

 or crude nitrate which averages three feet in 

 thickness. The crude nitrate is dissolved and 

 refined in boiling water in huge vats. The 

 water is run off and the nitrate is collected in 

 crystals like common salt. This is the nitrate 

 [72] 



