268 APPENDIX. 



" My own table, as will have been remarked, shows the 

 results for the soils of Iowa and Wisconsin to be — 



Average quantity of soluble organic matter - 4.80 per cent. 

 Average quantity of insoluble organic matter 5.13 

 Average specific gravity of soil - - - 1.84 





" The first result which strikes the eye is the large amount 

 of organic matter in the Iowa and Wisconsin soils, compared 

 with those of Massachusetts — nearly one-third greater. 



" The second is the great specific gravity of the ^Massa- 

 chusetts soil, compared with those of Iowa and Wisconsin — 

 nearly one-third greater. 



" A more careful inspection shows that the amount of 

 organic matter is, almost to mathematical accuracy, in the 

 inverse ratio of the specific gravity of the soils. 



" It would be a hasty inference thence to deduce the con- 

 clusion that soils are rich in geine, in proportion to their 

 specific lightness ; yet the coincidence, in this respect, is 

 marked and worthy of attention. 



" If further analysis of soils in various portions of this and 

 other countries should exhibit similar results, it would appear 

 that a simple trial of the specific gravity of a soil may, in a 

 general way, furnish an approximating test of its fertility. 



" Be this as it may, the dark mould which pi'evails over a 

 large proportion of Iowa and Wisconsin, so rich in geine, 

 and of so small specific gravity, has proved itself, wherever 

 the farmer has trusted to its certain returns, instead of attempt- 

 ing the more hazardous venture of the mine, an excellent and 

 productive soil ; especially adapted to the culture of every 

 species of culinary vegetables and small grain, and produc- 

 ing, probably, as good Indian corn as the State of New York, 

 or any other State of the same latitude. 



" It will be observed, from the table, that the power of 



