340 Mitieral Manures, and the Value of 



Magnesia, . . . . . . 0-280 



Phosphoric acid, . . . . . traces. 



Potash and soda, . . . . . 0-161 



Total acid extract, . .... 5-011 



Organic matter rendered soluble by ammonia, . . 3-140 

 " " " " " soda, . . 1-030 



Organic matter remaining in combination with the 



insoluble residue, and determined by ignition, . 1-720 



Insoluble silicates, . . . . . . .83-010 



100 parts of the insoluble residue gave by washing 

 and separation 59 parts siliceous, and 41 parts 

 clayey matter. 



Total amount of organic matter extracted by alka- 

 lies and acids, ....... 6-750 



Total per centage of the whole analysis, . . 97*637 



In the separation of the organic constituents of a soil by 

 means of alkalies, a slight loss is almost unavoidable, owing 

 to the separation and solution of a part of the alumina and 

 other inorganic substances in combination with the organic 

 matter, forming salts. 



In the examination and analysis of these soils of the Scioto 

 Valley, several points of interest were noted by me, which I 

 consider worthy of especial attention. Their reputation for 

 fertility is extensively known, as well as their general char- 

 acter and chemical composition, but I am not aware that any 

 extended and thorough examination of a suite of specimens, 

 from known localities, has heretofore been made by any 

 chemist. 



The first and perhaps the most interesting fact noticed in 

 the examination of these soils was the remarkable degree of 

 fineness of their constituent particles. In this respect I ven- 

 ture to assert that they are not surpassed by any other alluvial 

 deposits upon the surface of the earth, some of the soils being 

 little else than impalpable powders. In commencing their 

 examination, it was at once seen, that a mechanical division 

 of these soils by means of the sieves ordinarily used in soil 

 analyses, would not afford a fair indication of the minuteness 



