Ill 



TABLE III. 



PER CENT. OF CALCIUM OXID REMOVED BY VARIOUS SOLVENTS. 



SOURCE OF SAMPLE. 



I- 



o a 



3:2 § 



C t> ~ 



5 ^ ._ 



aos' 



— ^1 ri>~— ^1 HHi-ix 



:;-— a|«=—gi s^; 



03 



« 



Kentucky No. 3. 



Kentucky No. 1 . 



Turley 



Campbell 



Station 3 E. 1 . , 

 Stations E. 2. . 

 Station 3 E. 4. . 

 Station 3 E. 5. . 



0.144 



.122 

 .066 

 .114 

 .096 

 .089 

 .113 

 .105 



0.173 



.196 

 .122 

 .143 

 .216 

 .246 

 .226 

 .227 



0.51 



.31 



.447 

 .472 



It will be seen that the alkaline ammonium chlorid removes about one-fourth 

 and neutral ammonium chlorid about one-half as much lime as the hydrochloric 

 acid used in the customary method of soil analysis. The station soils are prac- 

 tically free from carbonates, containing an average of only 0.015 per cent, of 

 carbon dioxid. 



Of the solvents used we consider alkaline ammonium chlorid and neutral 

 ammonium chlorid promising for available potash, and ammonium hydrate prom- 

 ising for available phosphoric acid. Alkaline ammonium oxalate seems to do 

 very well for available phosphoric acid in some cases, but the material is rather 

 troublesome to work with on account of the large amount of organic matter that 

 goes into solution. Where ammonium chlorid is present the solutions are nearly 

 free from organic matter, filter very rapidly, and the ignition is readily made, 

 leaving only a small amount of bases to be removed before determining the potash. 

 Tatlock's method was tried for potash, but proved unsatisfactory. 



We have tried chlorids of calcium, magnesium, and sodium, but prefer to use 

 the ammonium salt, since it introduces no involatile base which would interfere 

 with the potash determination. 



We are now at work with ammonium hydrate, continuing the digestion for a 

 longer time and changing the strength of the solution. We are also testing am- 

 monium chlorid dissolved in 1 per cent, hydrochloric acid. We shall also test 



