272 ANALYSES OF SOILS. 



The wheat district, as we liave bounded it, extends from the south shore of Lake On- 

 tario, to a line drawn llirough the middle of Cayuga and Seneca lakes. It is not claimed 

 that tiie whole of this district is better adapted for wheat than for any other kind of grain ; 

 for on tlie south shore of Cayuga lake, much sandy soil is found, wliich is not well suited 

 to wheat, but is better for rye. This soil seems to be derived from the sandy parts of the 

 Medina sandstone, the strata of which are often well developed, and difler greatly from 

 the marly part of the rock noticed in the foregoing pages. 



The composition of the soil of this district is illustrated by the composition of the rocks 

 from which it is derived. We shall therefore give several analyses of the most important, 

 tiiose especially of the softer kinds, which furnish the greatest amount of material. The 

 first which we shall notice, and which seems to be the most liable to disintegration, is the 

 red shale, the lowest member of the Onondaga-salt group. Two varieties have been 

 noticed ; the sandy and the marly, or the soft red shale (juite destitute of grittiness, and 

 which is often spotted green. 



ANALYSIS. 



8AND7. MAKLT. 



Silex --. 68-25 68-86 



Peroxide of iron and alumina 6-25 14-98 



Magnesia 5-75 0-40 



Carbonate of lime 10-25 9-89 



Phosphate of alumina, and phosphate of 



peroxide of iron 0-00 0-14 j. 



Water 1-00 6-48 



, 99-50 99.25 



The sandy variety was taken from the horizontal rock at Canastota, which is now pene- 

 trated for a brine spring, and furnishes a tolerable amount of water. 



The most important fact brought out in the analysis of the rock, is its calcareous matter. 

 Magnesia also is a constant clement, but probably varies in amount at different places. 

 The marly variety forms by far the greatest proportion of the rock, and hence may be 

 considered as the part which gives character to the soil. Oljservation confirms the view 

 which we should fonn of the character of the soil derived from this rock. It is well adapted 

 to the wheat crop, and is slowly exhausted by cultivation. It is sometimes employed to 

 renovate soils which are partially worn out. 



The rock which succeeds the red shale, is a soft greenish marl, whose composition 

 continually varies by the presence of bands of gypsum. The red color disappears, while 

 the soft shaly nature of the rock continues : it therefore forms a soil quite similar to the 

 preceding. This mass may be known, however, not only by its green color, but by the 

 presence of cavities in the form of the hollow cubical crystals of salt, or chloride of sodium. 



The composition of this rock is as follows : 



