On Chalk Marl 



553 



Analysis of Lower Chalk (No. 9). 



Per Cent. 



Clay and sand insoluble in acids . . . 2*04 



Silicic acid, soluble in ditto .... trace. 



Carbonic acid 42-14 



Sulphuric acid . . . . . . '31 



Phosphoric acid . . . . . . "07 



Chlorine none. 



Lime 54-37 



Magnesia . . . . . • • '25 



Potash -08 



Soda -19 



Protoxide and peroxide of iron . . • '55 



Alumina ....... trace. 



100-00 



No. ]0. Lower Portion of Chalk, with Flints. — This is a 

 softer chalk than the preceding. It pulverises to a considerable 

 extent on exposure, but not thoroughly, like the upper member, 

 or free chalk next to be described. This bed (No. 1 0) is of in- 

 terest, as underlying, just beneath the surface, the greater part of 

 North Hants. 



Analysis of No. 10. 





Per Cent. 



Sand and silicious matter insoluble in acids 



•66 



Carbonic acid ..... 



. 42-98 



Sulphuric acid » . . . . 



. trace. 



Phosphoric acid ..... 



•08 



Chlorine ...... 



none. 



Lime 



. 55-24 



Magnesia ...... 



•10 



Potash ....... 



-06 



Soda ....... 



•14 



Oxide of iron and alumina 



•74 





100-00 



No. 11. The Upper Soft White or Free Chalk crumbles into a 

 fine powder, like slaked lime, on exposure. It is always selected, 

 where attainable, for the chalking of soils, for which purpose 

 enormous quantities have been dug, from time immemorial. At 

 Odiham, in North Hants, there is a pit of chalk of this descrip- 

 tion, probably the most extensive of its kind in the kingdom. 

 The specimen analyzed was taken near Crondell church, in a 

 field of about 100 acres, in several parts of which, by way of ex- 

 periment, bones were thickly applied as a manure some twelve 

 or thirteen years ago, after which there was a most marked supe- 

 riority in each crop of the four-course shift, the portions where 

 the bones were put being conspicuously visible in the crops. 

 There is a thin top-soil, of light hazel loam, lying on the chalk in 

 this locality. 



