PHOSPHORUS FERTILIZERS 159 



practically neutral, and can therefore be applied even to 

 germinating seeds or young tender leaves without injury. 

 It makes an excellent manure for a turnip crop, as it is not 

 in any degree acid, but supplies sufficient lime and phosphates 

 in an easily available form. Farmers not infrequently find 

 that this is a convenient material to dust on to young turnip 

 plants to ward off attacks by the turnip fly (see p. 246). 



REFERENCES TO SECTION III. 



Hemlock, " The Lime in Basic Slag," Journ. Soc. Chem. Ind., 1909, 

 p. 775 ; " The Lime in Basic Slag : A Correction and Addition," Journ. 

 Soc. Chem. Ind., 1911, p. 520. 



Wagner, " Bewerthung der Thomasmehle " (Verlagsbuchhandlung, 

 Paul Parey, Berlin). 



Collins' and Hall, " The Inter- Relationships between the Constituents 

 of Basic Slag," Journ. Soc. Chem. Ind., 1915, p. 526. 



Robertson, " The Influence of Fluorspar on the Solubility of Basic 

 Slag in Citric Acid," Journ. Soc. Chem. Ind., 1916, p. 216. 



Jones, " The Wagner Test as a Measure of the Availability of the Phos- 

 phate in Basic Slag," Journ. Bd. Agric., 1914-15, p. 201. 



Aita, " Rational Preparation of Superphosphates," Journ. Chem. Soc. t 

 1919 ; A. ii. 25, Journ. Soc. Chem. Ind., 1919, 23 A. 



Crowder, " Observations made on the Working of Vitriol Chambers," 

 Journ. Soc. Chem., Ind., 1891, p. 303. 



" Sulphuric Acid," Journ. Soc. Chem. Ind., 1919, p. 249 R. 



Wright, " On the Oxygen Content of the Gases from Roasting Pyrites," 

 Journ. Soc. Chem. Ind., 1914, p. m. 



Fawsilt and Powell, " The Action of Concentrated Sulphuric Acid on 

 Iron," Journ. Soc. Chem. Ind., 1914, p. 234. 



Falding, " Sulphuric Acid Leaden Chamber Construction," Journ. Soc. 

 Chem. Ind., 1909, p. 1032 ; 1913, pp. 21 and 360. 



" Reinforced Lead Sheets," Journ. Soc. Chem. Ind., 1919, p. 186 R. 



Barrs, "The Influence of Impurities in Lead on its behaviour when 

 heated with Concentrated Sulphuric Acid," Journ. Soc. Chem. Ind., 1919, 

 p. 407 T. 



Brenchley, "The Eradication of Weeds by Sprays and Manures," 

 Journ. Bd. Agric., March, 1919, P- M74- 



" Tetraphosphate of Lime," Journ. Soc. Chem. Ind., 1919, pp. 228 R, 

 401 R, 437 R. 



Parrish, " Drying Superphosphate," Journ. Soc. Chem. Ind., 1919, 

 p. 184 T. 



"Driving off Poisonous Gases," Journ. Soc. Chem. Ind., 1919, p. 397R. 



Herzberg, " Paper Sacks for Superphosphate," Journ. Soc. Chem. Ind., 

 1919, p. 458 A. 



" Agricultural Produce of the United Kingdom," Journ. Bd. Agric., 

 March, 1919, p. 1473. 



Utilization and Economy of Sulphuric Acid is specially discussed by 

 Partington in " The Alkali Industry," a volume of this series. 



Grinding Machinery is discussed by Da vis in " A ^Handbook of Chemical 

 Engineering," vol. i., pp. 455-518 (Hotspur Press). " 



