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On the Silica Strata of the Lower Chalk. 



243 



to the practical production of the double silicates for agricultural 

 use, but we shall probably have to return to this subject in a 

 future paper. We have only further to add one or two remarlcs 

 on the formation of this silicious deposit. It is not infusorial ; 

 for, with the exception of a few foraminifera, no traces of animal 

 life can be observed in the rock by microscopical examination. 

 It cannot have been subjected to heat of any intensity, or it would 

 have been rendered insoluble in alkalies. It is plainly the result 

 of aqueous decomposition ; and it seems very reasonable to 

 suppose that silicate of lime in solution, derived from the older 

 rocks, may have met with carbonic acid, produced either by 

 vegetable and animal decay, or by volcanic agency, and at one 

 and the same time carbonate of lime and gelatinous or soluble 

 silica would be formed. It should be remembered that we find 

 these beds in immediate contact with the chalk. We find chalk 

 without silica — silica without chalk ; and in other cases, as in the 

 building-stones, we have both intimately blended. There is, 

 therefore, very good reason for supposing that these productions 

 have been in some way connected. 



This is a speculation, however, of no great interest to the agri- 

 culturist, and we shall not carry it farther in this place. 



We think it right to state that the subject is by no means 

 exhausted ; but having given the results of our investigation up 

 to the present time, as it is obviously connected with many im- 

 portant agricultural questions, we shall probably give an account 

 of our extended inquiries on a future occasion. 



Alton, June 10th, 1853. 



My dear Sir, — A pressure of different professional matters has prevented 

 my attention to your request before. I inquired of Mr. Wm. Pampliii, of 

 River Hill Farm, at Binsted, as to the effects of lime on the 7nalm lands in 

 his occupation at that place. He states as follows : — 



" ' The beneficial effects of lime as a dressing on the malm lands would 

 scarcely be credited if not seen : there is no dressing like it. The lime I have 

 applied was white lime from chalk procured at Foyle — white chalk with 

 flints. I have usually applied 1 bushel per rod, and its effects are perceptible 

 for 8 or 10 years ; it can be seen to an inch where it has been laid by the 

 luxuriance of the crop, and it can even clearly be perceived where the dust 

 only has settled when the dressing was applied to other land. In one field of 

 mine a small part was missed in the last season — the wheat failed on that spot 

 of the field only. I am certain there are 500 blades on the limed part to 

 every 100 on the part not limed.' 



Mr. John Waterman, of Norton Farm, Selborne, in answer to similar in- 

 quiries, states as follows : — 



*' ' Part of the land in my occupation is malm land, on which 1 apply a 

 considerable quantity of lime, which works well, particularly for green crops, 

 and makes the berry of the cereal crops much finer. I have used it on the 

 clay lands, but with little advantage. The lime I use is made from the chalk 

 of Noah Hill — principally white. There is grey chalk under the white at 



R 2 



