VII. 



SPECIAL MANURES 



135 



the application of nitrate containing 1 per cent perchlorate decreased 

 the production of grain and straw about 4 per cent, while nitrate con- 

 taining 2 per cent lessened the grain by 25 per cent and affected the 

 straw to an even greater extent. 



De Caluwe l found that sodium perchlorate was more poisonous 

 than the potassium salt, rye and maize being the most susceptible 

 crops. The application of 150 grammes of sodium nitrate to the square 

 metre gave a crop of 6*7 kilogrammes with pure nitrate, but when the 

 nitrate contained 2 '67 per cent of sodium perchlorate the yield was 

 only 3-35 kilogrammes, while nitrate containing 4 to 5 per cent of the 

 perchlorate proved fatal in all cases. 



Sodium nitrate is the most important artificial source of nitrogen 

 and has taken the place, to a great extent, of guano ; as the supplies 

 of the latter substance have now been almost exhausted, it naturally 

 occurs to one that a similar fate may soon befall the supplies of nitrate. 

 Various estimates of the total available nitrate in ; the deposits of Chili, 

 Peru and Bolivia have been made, ranging from 63,000.000 to 

 178,000,000 English tons. In 1895 the total export from South 

 America reached 1,220,000 tons, while in 1910 -it was 2,285,000 tons. 

 The following statistics, giving the estimated total world's consumption 

 of nitrate of soda in the various years, may be of interest : 



During the earlier years, England consumed the greater portion of 

 the total production. In 1875, the amount consumed in the United 

 Kingdom was 165,000 tons, while the European continent used only 

 132,000 tons. In 1879, however, the continental consumption, for 

 the first time, exceeded that of the United Kingdom and since then 

 has enormously increased, mainly because of the development of the 

 sugar-beet crop, while that of this country has remained stationary 

 or even diminished. 



The table on the following page, giving the estimated consumption 

 of nitrate, in tons, for the years mentioned, will show how greatly 

 the use of nitrate has increased in other countries. 



Ammonium Sulphate. When organic nitrogenous bodies are 

 submitted to destructive distillation, i.e., heated strongly without ac- 

 cess of air, the nitrogen which they contain is, to a great extent, ex- 



. Assoc. Beige dee Chim., 12, 363 ; Jour. Soc. Chem. Ind., 1899, 114. 



