242 E. A. Schneider — Analysis of a Soil 



ing the corroboration afforded by the investigation of Dr. 

 Loughridge."* 



My own results seemed to confirm M. Schloesing's opinion, 

 as reference to the tables containing the analyses by fusion will 

 show ; since, however, it is possible that the large quantities of 

 water employed in mechanical analysis had leached out a con- 

 siderable portion of the alkalies and alkaline earths, I prepared 

 another portion of clay, by treating 100 grm of the soil with 

 5300 cc of distilled water and evaporating the resulting " clay 

 water" to dryness. 



The clay procured in this way gave the results under a, 

 while the clay, which was prepared in the ordinary manner 

 afforded these under b. Even if the higher figures of a were 

 not partly due to the presence of the soil extract they are still 

 lower than those obtained by analysis of the sediments 8 mm h. v. 

 — 64 mm h. v. which are given under c. 



a. b. c. 



CaO 2*60 per cent. -41 per cent. 6*55 per cent. 



MgO 2-30 " 1-57 " 2-59 " 



P 2 5 '65 " -11 " '33 " 



I give here also the analyses of b and o by extraction with 

 hot hydrochloric acid. 



b. c 



CaO '17 per cent. 3*01 per cent. 



MgO 1-16 " 1-06 " 



P 2 5 -11 " -14 " 



We see that the results obtained by extraction with hydro- 

 chloric acid are nearly proportional to those obtained by fusion. 



Why is it now that Dr. Loughridge found the clay of his soil 

 to be of all the sediments the richest in bases, while I have 

 found the opposite ? The coarser sediments of Loughridge's 

 soil contained "nothing but quartz-sand," as that author ex- 

 presses himself, while in the Rockland Ridge soil the coarser 

 sediments are the least decomposed fragments of a rock, which 

 is extremely rich in bases and phosphoric acid. 



I have not succeeded, unfortunately, in determining the 

 amount of alkalies in the clay, owing to the difficulty of pre- 

 paring the latter in a sufficient pure state for an alkali-determi- 

 nation ; I believe, however, that the alkalies would show a 

 decrease, probably in the same proportion as the alkaline earths. 

 The high percentages of alkalies which Loughridge found in 

 the clay that he analyzed may be partly due to the solution of 

 common salt with which the clay was precipitated. These con- 

 tradicting results seem to me to indicate that the truth about 



* On the distribution of soil ingredients among the sediments obtaiued in silt 

 analysis by R. H. Loughridge, of Oxford, Miss. Proceed, of the Am. Assoc, for 

 the Advanc. of Science, 1874. 



