daring the last Four Years. 181 



Marl is commonly applied in Cheshire to light soils at the rate of 

 128 cart-loads to the acre.* I have also had specimens of marl 

 so used sent from the New Forest in Hampshire. The greatest 

 improvement of recent times, the application of clay to peat 

 and peaty sand in Lincolnshire and the wide district of the fens, 

 by which in one instance^ as we learn from Mr. Wingate.f 

 on land which had been almost worthless, two white crops had 

 been grown every three years, one of them wheat, yielding 40 

 bushels per acre, — an unexampled rotation, not used, however, 

 only when the land was fresh, but continued for eighteen years ; — 

 this improvement, which equals anything that has been done in 

 Flanders, is another instance of the same principle. It is, there- 

 fore, important to examine the facts accurately : as yet, however, 

 we have not the means. 



The substance applied is sometimes called marl, sometimes clay. 

 Of the specimens I have received, even those which were called 

 clay, have generally turned out to be marl, for they contained lime, 

 which constitutes the distinction. The difference, however, is 

 important, because marl is a much rarer substance than clay; 

 and if lime be an indispensable ingredient of clay fit for 

 manure, many districts of England must be cut off from this 

 source of improvement. I am inclined, however, to hope that it 

 is not indispensable. One specimen of the Lincolnshire clay 

 which I have examined certainly was not a marl. Again, the 

 Flemings, as Mr. Rham^ informs us, have converted their sandy 

 desert into one of the most fertile districts of Europe by bringing 

 up year after year 2 inches of subsoil from trenches shifted each 

 year, until they reached a depth of 2 feet. Their sands, I be- 

 lieve, rest often upon a yellow clay, and their fields have in some 

 places the singular appearance of light sand on the surface, while 

 water is standing in the ditches 2 feet below. I do not think that 

 the clay of the Netherlands contains much lime. I have met 

 with an instance of a strong clay without lime in Suffolk, which 

 has been applied to a poor light calcareous soil, and paid itself 

 the first year in the clover-crop. § Near Reading, too, the same 

 effect has been produced by the clay dug out from the railway on 

 a thin burning gravel. That clay is certainly not a marl. We have 

 also a striking account II in our last Number of the application of 

 blue shale to a field of gravel and sand, on which dung and bones 

 had equally failed to produce either turnips or barley, yet 50 

 cart-loads of this shale brought on each acre 40 bushels of barley. 

 Now shale is clay half hardened into blue slate. I do not know 



* Mr. Cuthbert Johnson on Fertihzers, p. 271. 

 '(• Journal, vol. ii. p. 408. % Outlines of Flemish Husbandry. 



^S Prize Essay of East Suffolk Agricultural Association, by Captain 

 Alexander. || Journal, vol. iii. p. 161. 



