INTRODUCTION AS A MANURE 



11 



SULPHATE OF AMMONIA PRODUCED IN THE UNITED KINGDOM 



The greater part of the sulphate of ammonia produced in 

 this country is exported, chiefly to France, Germany and 

 Belgium. The Inspector of Alkali Works states that in 1886, 

 the home consumption of sulphate of ammonia amounted to 

 22,000 tons ; and in 1897 to 70,000 tons. 



With this great increase in the quantity produced there has 

 been a great fall in the price of the salt. The average whole- 

 sale price of sulphate of ammonia in 1881 and 1882 somewhat 

 exceeded 20 per ton ; its average price in 1896 and 1897 was 

 j i8s. od. per ton. 



THE INTRODUCTION OF AMMONIACAL 

 MANURES 



That ammonia salts were capable of acting as a powerful 

 manure was apparently unknown till modern times. The 

 supply of ammonia salts was indeed too limited, and their cost 

 too considerable to favour any experiments being made with 

 them in this direction. W T hen, at the commencement of the 

 present century, agricultural chemistry had made some progress, 

 it was recognised that ammonia acted as a plant food, and was 

 capable of supplying the nitrogen needed for the formation of 

 vegetable albumin, and the other nitrogenous constituents of 

 plants. In Sir Humphry Davy's " Elements of Agricultural 

 Chemistry" (1813), we find several references to the manurial 

 power of ammonia. In his lecture on Manures of Mineral 

 Origin he describes some experiments of his own on the 

 subject. He says : 



"Much of the discordance of the evidence relating to the 

 efficiency of saline substances depends upon the circumstance 

 of their having been used in different proportions, and in 



