208 ])ETERMIXATIOX OF rHOSPHORIC OXIDE. 



to the Tolumetric modification used in this hiboratoiy, and 

 eig"hteen years had passed since Lorenz wrote the above. 

 We haA'e been unable to find any reference to liis having" 

 undertaken the analysis of the precipitate. Xeubaner and 

 Liicker in 1912 make no mention of any such work by 

 Lorenz. 



Finally, we desire to thank Mr. B. J. Smit, Assistant 

 Chemist, Division of Chemistry, for the results quoted on 

 pp. 204, 200 and 2()T. 



SOME FURTHER FACTORS IXFLFEXCIIS^G THE 

 SOLUBILITY OF PHOSPHORIC OXIDE IN 

 MIXED FERTILISERS COXTAIXIXG SUPER- 

 PHOSPHATES. 



By Edmuxd Victor Flack, 



Affsisfcmt AfjricuJturdl Chetnist, Sahsburj/. 



Bead Juhj 15, 1920. 



The question of sui)plies of ingredients for compounding- 

 fertilisers during' recent years has been a matter of serious 

 consideration for those eng-aged in the trade, owing to 

 shortage of materials imi)orted from overseas. Since the 

 publication of my ])revious article on " Some factors 

 influencing- the solubility of phosphoric oxide in mixed 

 fertilisers containing super])hosphate " (South African 

 Journal of Science, xiii, 201-208, Dec, 1910) there were 

 several mixtures other than those mentioned in the al)ove 

 paper which affect the solubility of phosphoric oxide. 



