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beneficial to the land, after the second, third, or fourth year; 

 a fact which I attribute to the gradual escape of the astringent 

 matter by the rain. Though I do not think that the exposure 

 of even an entire winter will always suffice to rob the clay of 

 all the sulphates (copperas, &c.) which it may contain, yet it 

 bids fair to do much good, and therefore deserves a careful 

 trial. 



I have to offer another, and I think, far more promising sug- 

 gestion, for making the better portions of this stratum beneficial 

 in their effects upon the soil. Chemists are aware that both the 

 sulphate of iron and the sulphate of alumine are decomposed by 

 caustic lime ; and the antidote I propose is founded upon this fact. 

 My recommendation is, to add to every heap of this spurious 

 astringent marl, a small quantity oi freshly burnt lime, and to 

 mingle them thoroughly together. The sulphuric acid of the 

 copperas or alum earth, or of both if present, will pass over to 

 the lime and form sulphate of lime (gypsum or plaster), the value 

 of which, as a stimulant to vegetation, is well understood ; the 

 other ingredients, the oxide of iron and clay, will on being libe- 

 rated, contribute also towards improving the texture of the soil 

 should it be sandy. A bushel of lime to every hundred bushels 

 or five tons of the mass, will in most cases be sufficient to neu- 

 tralize all the astringent matter present, and to convert it into, or 

 rather replace it by, gypsum. The dressing of an acre of such a 

 mixture will contain of the green marl, of gypsum, and of uncom- 

 bined lime and lime in a state of carbonate, in all probability fully 

 enough to impart to the soil a most decided improvement in point 

 of fertility. 



Lastly, I would recommend, for this astringent marly clay, the 

 same course so appropriate also in regard to lime: I mean the 

 practice of making a compost of the substance with the common 

 manure of the farm. 



This, like the former suggestion, is justified by good chemical 

 reasons. In the fermentation of animal manure, ammonia always 

 escapes in greater or less quantity; and ammonia, like lime, has 

 the power of decomposing the sulphates of iron and alumina. 

 In this case, however, gypsum is not a product. 



From what is here said, it will be obvious, that when a field 

 has been made sterile by the indiscreet use of this caustic clay, a 



