WESTERN DISTRICT. 271 



rock. There is, it is true, some show of tnilli in this view of the ((iiestion ; nevcrtheh'ss, 

 the view is falhicious, and has hut a small foiiiulation to siippoil it. Calcareous matter is 

 an important element in a wheat soil ; but this is not all, and even if it were so, the Onon- 

 daga limestone would fail to fin-nish the amount reipiired to fertilize this large district. 

 Now in looking about us for the solution of this question, we fnul that the true elemeuls 

 of the wheat soil exist mainly in the shales associated with the limestones, particularly 

 those of the Onondaga-salt group. In addition to these, the rocks of this group, the gray 

 and red marl of the Medina sandstone, and the shales and slates of the Ontario division, 

 exert an important influence on the soil, which bears favorably upon the growth of wheat. 

 In support of this view, we may observe that the Onondaga and Niagara limsetones are 

 but slowly converted into soil ; they are too hard and compact to be reduced to the condi- 

 tion required : hence, we regard them as performing an inferior part or office in this matter. 

 The cause is truly geological ; but the part these comparatively pure limestones perform, 

 is quite subordinate to that of the shales and marls. This is necessarily true, from the 

 feeble action of the weather and other decomposing agents on these rocks, as well as the 

 nature of the product which is produced by these causes. The debris of the pure lime- 

 stones does not favor the growth of the crop with the same power and permanence as the 

 debris of the shales, neither mechanically nor by composition. 



The rocks which have been just referred to as those which give to this district its dis- 

 tinctive crops, extend from the base of the Ontario division, the Medina sandstone, to the 

 Onondaga limestone, the upper rock of tlie Helderberg division. By reference to what 

 has been already said of the lower members of this last division, it will be seen that they 

 are largely developed in the district under consideration, but it is known that they do not 

 extend to the limits of this district on the south. There is no difficulty on this point, so 

 long as it is plain that the debris of the fragile and easily decomposing masses are found far 

 south. To the transportation of this debris of the shale, must be attributed the extension 

 of the wheat district beyond the limits of the rocks which give origin to it. They have 

 been used abundantly for this purpose, and their nature aids materially this process ; while 

 the hardness of the limestone, and its small depth compared with the shales, disqualify it 

 to perform the office assigned it. An inspection of the materials proves the position we 

 have taken. A perceptible quantity of the peculiar debris of the shales can always be 

 discovered in the wheat soil, and may be known by the peculiar color which it imparts to 

 the soil. 



An inspection of the nature and composition of the soil explains to us the reason why 

 this district is more productive in wheat than those adjacent to it. Where the soil is thin, 

 but reposes upon the shales of the Salt group, additional matter is added to the former soil, 

 by the rapid decomposition of the rocks at or near the surface ; and where we detect, by 

 ocular inspection, the small angular masses of the shaly limestones of the gypseous rocks, 

 or find a soil of the peculiar drab color of those of Onondaga and Livingston counties, we 

 may be satisfied that it will produce wheat, and that this is its natural crop. 



