of the Rocks of the Coal Formation. 



145 



/' 



99-761 



No. 7. Muscle-Bind. — Sp. gr. 2-592 ; in thickness, six inches ; is 

 a clay-ironstone thickly imbedded with indurated shells of a brown 

 colour and very brittle. This bed resembles the muscle-bind of the 

 Derbyshire and Yorkshire coal-fields ; and is found also in the coal- 

 fields of Scotland. It lies in this instance at the depth of 62 fathoms 

 from the surface, or 9^ feet above the '* Low-main coal." 



® to 

 ua ^ 



Composition. 

 Organic matter and water of combination, 

 Protoxide of iron, . , . . 



Manganese, traces. 

 Alumina, . 



Lime, ...... 



\ Magnesia, ..... 



Chloride of sodium, traces. 



Potash, ...... 



Silicic acid, traces. 



Carbonic acid, .... 



f Oxide of iron, traces. 



I Alumina, ..... 



Lime, ...... 



Magnesia, ..... 



Silicic acid. ..... 



11-221 

 18-637 



1-194 

 4-084 

 1-078 



1-319 



14-057 



51-590 



16-292 



0-988 



0-288 



31-068 



48-636 



100-226 



No. 8. Cannel Coal. — Sp. gr. 1*319 : — is a black, homogeneous 

 mass, hard, brittle, and capable of taking a fine polish, fracture con- 

 choidal. Though not in the section of " Buddie's Hartley,'* is often 

 found in connection with the coal, as roof, base, or even interstrati- 

 fied with it ; that analysed is a fine specimen from •* Blaydon Main" 

 colliery, in Tyneside. 



VOL. L. NO. XCIX.— JANUARY 1851. K 



