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K 2 O-^Not deficient, though not abundant. 

 P%Oz '12 to '13% is considered a good average in 

 England. Of no class of Indian soils examined except the 

 soils from Meerut district and the coffee soils of Sheveroy 

 hills, Madras, can it be said that it comes up to the English 

 standard. Dr. Leather is obliged to admit that Dr. Voelcker's 

 ppinion that phosphoric acid is " more abundantly distributed 

 in Indian than in English soils" is erroneous. Some of the 

 soils of the Meerut district only analysed by Dr. Leather 

 contained as much as 4 a per cent, of PgOs. 



78. But although the proportion of total phosphoric acid 

 in Indian soils is decidedly meagre, the proportion of avail- 

 able phosphoric acid is not usually deficient, and it is the avail- 

 able phosphoric acid that immediately affects the question of 

 fertility or of produce. The application of bones has not been 

 attended with any very beneficial results in India, except in 

 a few isolated cases. This shows that the proportion of 

 available phosphoric acid is probably high. Dr. Bernard 

 Dyer of London has discovered an empirical method of find 

 ing out the available phosphoric acid and potash in soils. 

 This consists in submitting soils to the action of i/ solution 

 of Citric acid for 7 days and determining the proportion of 

 P2Os and KgO in the solution. Dr. Dyer aimed at demons- 

 trating whether the results of such treatment would corres- 

 pond with the known fertility of some of the standard soils of 

 the Rothamsted Experimental Farm. The result of the 

 research showed conclusively that a very close correspond- 

 ence exists between the amount ot phosphates and potash 

 thus dissolved from the soils and their known fertility in the 

 matter of phosphates and potash. Dr. Dyer concluded from 

 his research that " when a soil is found to contain as little as 

 about *oi per cent, of phosphoric acid soluble in a i% solu- 

 tion of Citric acid, 'it would be justifiable to assume that it 

 stands in immediate need of phosphatic manure." Dr. Leather 

 applying Dr. Dyer's method in a few cases showed that even 



