GEOLOGY. . 267 



the salts in any soil exert upon the organic matter a chemical 

 action, and contribute to regulate and facilitate the process 

 of nutrition. Without an adequate supply of saline material, 

 then, a soil lacks one of the essential ingredients of 

 fecundity. 



" To form an estimate, from the above table, of the quality 

 of the Wisconsin soils, it is necessary to compare its results 

 with similar results obtained in countries in which, by actual 

 culture, the value of the soil has, to some extent, been 

 proved. The difficulty here is, that such analyses of soils 

 have very rarely been made or recorded. Professor Hitch- 

 cock, in his Report, of the year 1838, on the Economical 

 Geology of Massachusetts, furnishes a valuable table of this 

 kind, exhibiting the analyses of one hundred and twenty -five 

 specimens, which, as he informs us, may be considered as 

 about the average quality of the soils of that State. He 

 adds : ' As this is probably the first attempt that has been 

 made to obtain the amount of geine in any considerable 

 number of soils, we cannot compare the results with those 

 obtained in other places. They will be convenient, however, 

 for comparison with future analyses.' 



" And they do accordingly furnish data for a comparison, 

 both interesting and important, between the soil of Massa- 

 chusetts and that of Wisconsin. 



" The following are the results obtained from Professor 

 Hitchcock's table : 



Average quantity of soluble geine (organic 



matter) ------ 3. 90 per cent. 



Average quantity of insoluble geine (organic 



matter) - - - - - - 3.70 per cent. 



Average specific gravity of soil - - - 2.44 " 



