262 



ANALYSES OF SOILS. 



M.M'S. 



DUMMERSTON. 



ADDISON. 



ILDUrtnil. 



■ •! magnesia.. . 



50-08 



as. i" 



8-09 



17*34 

 21-13 



1 •-.'! 



16*18 



ao" 



12-40 

 3*' is 



1 side "i mangani 







The variation in composition would appeal still farther by othei analyses: thus, the 

 silex in some of the \ ermonl concretions amounts to 29*08 ; the alumina varies from 7*30 

 to 28" 10 per cenl ; the peroxide of iron, from L* 73 to 8*81 per cent. 



Sulphate of Lime, which is a common substance in the Albany clay, is not found in the 

 concretions. The Largest and most spherical ones seem to-be formed where carbonate 

 of lime is in the greatest abundance. In man) instances, the same material which forms 

 the claystone, forms, in the clay beds, distinct Layers, in some of which silex instead of 



onate of lime is the pred inant ingredient. The force which produces a concretion 



is closely allied i<> thai of crystallization, for their is a tendency to build up regular sym- 

 metrical solids. It is active in all Bemiconsolidated materials, as paste, mortars and clays ; 

 and it always begins at a centre, ami extends m the direction of the radii of a sphere. 



Paring and ui'rnin<j of clay soils. 

 In this place the question comes up, what changes should clays he made to undergo, in 

 order to become tilted for cultivation? Some maintain that the iron contained in clay is 

 converted b) combustion into a peroxide ; the former state of the iron being noxious, and 

 the lattei congenial to wgetation, or else becoming so by its relations to other elements 

 existing in the soil. Others suppose that it is the Bulphuret of iron, existing in clay soil, 

 which is converted into the peroxide l>\ burning; and that the sulphuret of iron is injurious 

 lo vegetation. This opinion can not be correct, unless indeed the sulphuret is of that kind 

 which decomposes and forms sulphate of iron, which, in large doses, is unquestionably 

 injurious to plants. We can hardly believe that sulphuret of iron is at all injurious, unless 

 it is undergoing decomposition. Admitting the correctness in part of this view, still the 

 mechanical effect of the burning is fan more important than the chemical effect. Clay, 

 a- deposited, is close, impervious, or difficult to lie penetrated by the roots of plants. Two 

 effects follow from hurtling: 1st. The soil is rendered open, pervious, and penetrable; 2. 

 Some of (he matters in the clay become more soluble. This is maintained by Liebig, \\ ho 

 support- his view of the subject by reference to the greater solubility of argillaceous earths 

 in acids after they are ignited, than before. Ii i- true, we believe, however, that the peroxide 

 of iron doe- exert a salutary influence on vegetation ; and this opinion is supported by the 

 character of the productions of a brick red soil. This is certainly found to be a warm soil, 

 tin-re being a perceptible difference in favor of the growth of grass and grain on lands of 

 this color; and it would seem that sheep and cattle are fond of grazing upon these soils, 

 and give them a preference! It appeals, then, 1st, that the burning of clays of any kind 



