AGRICULTURAL CHEMISTRY AND GEOLOGY. 



165 



earth thrown in above in levelling and making fair the field. It is preferred that the sod-side 

 of the superincumbent earth should be downwards. This relation of the balls gives a clear 

 thoroughfare for the drainage water through the central space enclosed by each set of four 

 balls, as in fig. 2 ; at the same time there are three half passages or thoroughfares for the 

 water at the bottom and top of the ball layer, and one half passage on each side. Hence 

 there is always a free passage for the water to drain down, and percolate through the enclosed 

 spaces due to the contour of the balls, getting clear away along the slate base of the drain 

 channel to the main outfall. 



Captain Norton illustrates his contrivance under several forms, the balls being variously 

 disposed in the drain cuts, while, in one instance, three several sizes of balls are used in com- 

 bination. Drains made in this way always present a full, free passage for the descent of the 

 water, as the spaces between the balls can never be diminished except by the introduction of 

 other solid bodies ; and the roundness of the balls is itself a point in favor of the avoidance 

 of such foreign deposits ; like the links of a chain, the balls will always conform to the ac- 

 tual surface of the ground, and no sinking can effect any serious dislocation, or prevent the 

 drainage from being full and free. 



Analysis of the Ashes of Oak and Pine Leaves, and their Comparison with 



those of Cotton and Corn. 



At the request of the Black Oak Agricultural Society, of South Carolina, Prof. C. U. Shep- 

 herd has recently analyzed the ashes of the oak and pine leaves, together with those of the 

 cotton and corn plants, with a view of ascertaining the value of the former as a manure for 

 the latter, so far as the mineral ingredients of the oak and pine leaves are concerned. From 

 the published report of Prof. S. we derive the following particulars : — 



" The agreement between the ashes of the pine and of the oak leaves, in regard to soluble 

 and insoluble substances, is striking ; the ratio being as one to twelve in pine-leaf litter, and 

 as one to thirteen in that of the oak ; while a very remarkable contrast subsists between their 

 contents of carbonate of lime and magnesia and of silica. The carbonate of lime and of 

 magnesia in one hundred pounds of oak-leaves is six times greater than in the same weight of 

 pine-leaf, while the silica of the latter surpasses that of the former by two and a half times. 

 In all other respects the difference between the two species of ash are inconspicuous. 



"Prof. Shepherd states that one hundred pounds of pine or oak leaves contain but one- 

 third the quantity of the highly-important alkaline carbonate requisite for one hundred pounds 

 either of cotton or corn ; but as this ingredient is afforded to some extent by all clayey soils, 

 through the gradual decomposition of the feldspar and mica they contain, it seems probable 

 that this amount of leaf-litter would be adequate to maintain the soil in fertility for both of 

 these crops.* 



Table, showing (in poxmds and decimals of pounds) the Mineral Constituents in 60 pounds Indian Com, 

 in 60 pounds Pine-Leaves, and in 60 pounds Oak-Leaves. 



" One hundred pounds (or rather one hundred and ten pounds, making allowance for hygro- 

 metric moisture in the atmospherically dry leaf) of either of these kinds of leaf-litter will 

 fully supply the phosphates indispensable for the same weight of cotton and corn; while of 

 the less important carbonates of lime and magnesia, it will (except in the case of the pine- 

 leaf for cotton) generally give a large surplus. In the one hundred pounds of pine-leaves, 



* Still it might be useful to add, along with this quantity, all the wood-ashes at command upon the plantation. 

 These usually contain about fifteen per cent, carbonate potash. 



