SCIENCE BULLETIN, No^ 10. 



was filtered. Of this filtrate 500 c.c. was evaporated to dryness with nitric 

 acid, ignited, moistened with hydrochloric acid, and heated for some time. 

 The residue was then moistened with hydrochloric acid, taken up with hot 

 water and filtered. This operation was repeated to ensure the removal of 

 all silica, and the P,O 5 precipitated and estimated as before. 



In each case the amount of moisture present in the soil w r as deter- 

 mined, and the results calculated as percentage of P,O 3 present in the dry 

 soil. 



A trial estimation of the amount of P 2 O. soluble in carbon dioxide 

 solution was made, following the method described by Wiley in his 

 " Principles and Practice of Agricultural Analysis," Vol. I, page 386. 

 Owing to mechanical difficulties involved, the method was discarded as 

 impracticable. It may be mentioned that in the soil used (a Wagga 

 sample) the amount of P,O 5 thus determined was only -00008 per cent. 



The following is a table of the results obtained, the P,O. being 1 calculated 

 as amounts present per 100 of dry soil : 



TABLE IV. -Showing Total and Available Phosphoric Acid. 



Subsoil. 



It will be seen that only in some cases were samples of the subsoil sub- 

 mitted, and in view of this ini-ompleteness, the figures relating to the 

 Subsoils may be discarded, 



