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JOURNAL OF THE 



nately that in all these instances the amount carried through was 

 very slight (hardly enough in the worst case to make any appreci- 

 able change in the results), being most in the case of the ammo- 

 niated fertilizer, less in the case of the acid phosphate and least of 

 all (almost absolutely none) in the case of the orchilla. 



The mechanical effect of the NaCl solution, as a wash, was per- 

 fect, no particle whatever in either case passing the filter, and fil- 

 trates being consequently crystal clear. 



Following are the results reached : 



^ , .,, ( Water wash, percent. " insoluble," PgO., 11.62 

 I NaCl wash, II-75 



Ammoniated Fertilizer 



Water wash, per cent, "insoluble," PoO. 

 NaCl wash, " " " '« 



1.97 

 2,25 



Arid Phn<;nhate^ ^^^^'^ '''^^^' P^' ''^"^- " insoluble," P2O5, I.I4 

 Acid Phosphate -j ^^(3j ^^^^j^^ " " " " 1.16 



While these results do not show that the NaCl solution has abso- 

 tiitely no effect on insoluble phosphate, yet they do show conclu- 

 sively that if it has any effect at all it is so slight that it does not 

 equal the loss by the water wash in three cases where the loss by 

 the water wash vjsl^ unusually ^ma\\; being, for example, practically 

 nothing in the case of the orchilla. 



I am of the opinion that it has no effect on the insoluble phos- 

 phate whatever, certainly not enough to prevent its immediate and 

 confident adoption as a substitute for water wash in all analyses. 

 Be it observed also, in the above experiments, that the case of the 

 greatest disparity in the results was the case where most of the sub- 

 stance passed the filter with the water wash. And in every instance 

 the results from the water wash are observed to be smaller than the 

 results from the NaCl wash. 



N. C. Agricultural Experiment Station, March, 1885. 



