552 



On Chalk Marl 



Insoluble in acids, 21*35 : — 



Lime ..... 

 Magnesia .... 

 Potash ..... 

 Soda ..... 

 Alumina and a little oxide of iron 

 Silicic acid and sand 



Per Cent. 



1- 71 



trace. 

 •32 

 •07 



2- 57 

 16-68 



100-00 



No. 8. — This rock is of a harder texture than the preceding 

 one, and falls to pieces in flakes, instead of into powder, when 

 exposed to frosts ; it has therefore never been so much esteemed 

 for marling purposes, neither is the soil formed from this rock 

 so naturally fertile as any of the preceding. It will grow good 

 wheat and barley, but it requires more manure. It is not suited 

 for hops. 



Analysis of Marl (No. 8). 

 Soluble in dilute acids, 92*74: — 



Silicic acid (silica) 

 Carbonic acid 

 Sulphuric acid 

 Phosphoric acid 

 Chlorine 

 Lime . 

 Magnesia 

 Potash . 

 Soda . 

 Protoxide and peroxide of iron 

 Alumina .... 

 Insoluble in acids, 7*26 : — 



Lime ..... 

 Magnesia .... 

 Potash ..... 

 Soda . . 



Alumina with a little oxide of iron 

 Silicic acid and sand 



Per Cent. 

 2-11 

 36*73 

 •06 

 •05 

 •04 

 49*16 

 1-18 

 •11 

 1*36 

 1*74 

 •20 



•22 



trace. 

 •15 

 •05 

 1^42 

 5*42 



100*00 



No. 9. Lower Chalk. — This is an extremely hard chalk, of rather 

 a yellowish colour. It lies between the preceding marl and the 

 chalk, with flints. It is very much mixed up with broken chalk 

 fossils, which, however, are non-phosphoric. Frost exerts very 

 little influence over this chalk, causing it merely to split into 

 laminated plates. It is seldom employed as a dressing for land. 

 As a soil, it is usually of a poor character, probably the poorest 

 of the whole series ; but after deep subsoiling, combined with 

 proper manuring, Mr. Paine has succeeded in growing upon it 

 heavy crops of wheat, barley, and turnips, even when there was 

 a very scanty portion of surface-soil. 



