INORGANIC NITROGEN FERTILIZERS 103 



ammonia. A particularly interesting use of this method 

 of oxidizing ammonia to nitric acid is in conjunction with 

 sulphuric acid leaden chamber systems, with which it is 

 quite unnecessary to go further than to produce nitric oxide, 

 which can be blown directly into the exit from the p}^rites 

 burners. For such a purpose quite a small plant is sufficient. 

 Pure ammonium nitrate contains 35 % of nitrogen, the 

 samples commonly produced being about 96 % pure, and 

 containing just over 33 % of nitrogen. It has an advantage 

 over ammonium sulphate in that it contains nothing that 

 is valueless for manurial purposes. L,ike many other very 

 soluble materials, it often condenses much moisture from 

 the air, but it does not differ very much from nitrate 

 of lime in this respect. The deliquescence of ammonium 

 nitrate, like that of any hygroscopic material, can be miti- 

 gated to some extent by dusting the crystals with any very 

 fine dry non-deliquescent powder. (See p. 150.) 



REFERENCES TO SECTION I. 



AMMONIA. Report, " Sulphate of Ammonia Association," Journ. Soc. 

 Chem. Ind., 1918, p. 441 R. 



Salmang, " Ammonia Production by the Gasification of Coal and 

 Coke in the Presence of Steam and Air," Journ. Soc. Chem. Ind., 1919, 

 p. 452 A. 



Maxted, " Notes on the Catalytic and Thermal Syntheses of 

 Ammonia," Journ. Soc. Chem. Ind., 1918, p. 232 T ; " The Synthesis of 

 Ammonia and the Oxidation of Ammonia to Nitric Acid," Journ. Soc. 

 Chem. Ind., 1917, p. 777; 1918, p. 368 A; 1919, pp. 219 A, 944 A. 



Haber, " Modern Chemical Industry," Journ. Soc. Chem. Ind., 

 1914, p. 49 ; " Technical Preparation of Ammonia from its Elements," 

 Journ. Soc. Chem. Ind., 1913, p. 135. 



Teed, " The Chemistry and Manufacture of Hydrogen " (Arnold). 



Hofmann, Arnoldi and Hiendlmaier, " Iron Cyanogen Compounds," 

 Journ. Chem. Soc., 1907, A. i, 196. 



Calvert, " The Manufacture of Sulphate of Ammonia," Gas World, 

 1911. 



Collins, " The Absorption of Arsenic by Barley," Journ. Soc. Chem. 

 Ind., 1902, p. 212. 



Partington, " The Oxidation of Ammonia," Journ. Soc. Chem. Ind., 

 1918, p. 33 8 R - 



Walpole, "Lessons from Germany," The Chemical Age, 1920, pp. 



29, 36. 



NITRATES. Newton, " The Nitrate of Soda Industry in Chili," Journ. Soc. 

 Chem. Ind.. 1900, p. 408. 



Hobsbaum and Grigioni, " Production of Nitrate of Soda in Chili 

 Past, Present and Future," Journ. Soc. Chem. Ind., 1917, p. 52. 



" The Nitrogen Problem and the Work of the Nitrogen Products 

 Committee," Journ. Soc. Chem. Ind., 1917, p. 1196. 



