0)1 Chalk Marl 



551 



Analysis of the Fossiliferous Green Marl (No. 6). 



Per Cent. 



Combined water and a little organic matter 



4-21 



Soluble in dilute acids, 64*61 : — 

 Silicic acid (silica). 

 Carbonic acid 

 Sulphuric acid 

 Phosphoric acid 

 Chlorine 



Lime .... 

 Magnesia 

 Potash 



Soda .... 

 Protoxide and peroxide of iron 

 Alumina 

 Insolubre in acids, 31 • 18 : — 



Lime .... 



Magnesia 



Potash 



Soda .... 

 Alumina and a little oxide of 

 Silicic acid and sand 



. 31-88 

 small quantity, undetermined. 



•45 

 3-76 

 trace. 

 . 5-61 

 •85 

 . 3-21 

 1-20 

 . 16-91 

 •74 



iron 



1-52 

 1-09 

 •45 

 •31 

 5-75 

 22-06 



100 00 



We have elsewhere drawn attention to the composition of this 

 remarkable marl, and shall only here observe, that, in addition to 

 the unusual percentage of phosphoric acid and potash it contains, 

 it is not unlikely that some part of its fertility is connected with 

 the quantity of silica present in a soluble condition. 



No. 7. Grei/ Marl. — The grey or dirty- white marl rests upon 

 the green band. It is frequently from 50 to 100 feet in thick- 

 ness, shading off into the next division. This of all others is the 

 marl which has been most extensively applied as manure in all 

 parts of the outcropping of the chalk hills ; and in very remote 

 times it seems to have been most highly appreciated, if we may 

 judge by the quantities that have been excavated. In some 

 localities it is denominated malm." On exposure to weather it 

 falls into a fine powder. We need hardly observe that it is a most 

 fertile subsoil, suitable to the growth of almost every crop. 



Analysis of the Grey Marl, or " Malm " (No. 7). 

 Soluble in dilute acids, 78 • 65 : — 



Silicic acid (silica) 



Carbonic acid 



Sulphuric acid 



Phosphoric acid 



Chlorine 



Lime . 



Magnesia 



Potash . 



Soda , 



Protoxide and peroxide of iron 

 Alumina .... 



Per Cent. 



2-16 

 29-96 

 •21 

 •21 



•08 



52 

 ■30 

 26 

 •64 

 20 

 •11 



41 



