CH. viii] Mineral Phosphates 153 



and acted on the phosphate with the acid solution 

 collecting round the anode during the electrolysis of 

 sodium chlorate, then precipitated with the alkaline 

 solution from the kathode, and finally filtered to re- 

 cover the sodium chlorate which was once more electro- 

 lysed. The material is found to be satisfactory^. 



Sometimes mineral phosphates themselves are ground 

 and sold as fertilisers but no great quantities are used 

 in this country. Beneficial results have been obtained 

 in many parts of the United States, especially on sour 

 derelict land^. Moorland soils also frequently respond to 

 mineral phosphates. Neither of these results, however, 

 affords much guidance as to what other soils will do ; in 

 particular, moorland soils respond more than others to 

 fertilisers of low solubility. Increased crops, however, 

 have been obtained at Cockle Park in Essex^ and also 

 at Aberdeen where dung was applied, but not other- 

 wise*. There is some evidence that finer grinding would 

 lead to better results. 



^ Von Feilitzen, 8th Congress, Applied Chemistry, vol. xv. p. 85; also 

 Journ.fu) Landw., 1910, p. 33, and 1911, p. 371. 



^ A summary of the American investigations is given in Journ. Agric. 

 Research, 1916, vi. 485. 



3 Guide for 1913, pp. 39, 40. 



^ Aberdeen Bull. No. 10, 1909. For a general summary of the effects 

 of the mineral phosphates see the author's Notes on Fertilisers, Journ. 

 Bd. of Agric, Feb. 1917, and May 1917. 



