428 Geological Inquiries, 



4. What are their several dimensions ? 



5. Are they nearly of the same thickness at different depths ? 

 Do they terminate in a wedge ; and this, at the top or bottom 

 of the vein ? 



6. Is their longitudinal course straight or curved ? 



7. Is it of uniform breadth, or does it enlarge and diminish ? 

 S. Do they ramify, and in what direction ? Do the branches 



re-unite ? 



9. In what order are the minerals arranged, of which the vein 

 is composed ? 



10. Are tliere any fragments of other rocks, any pebbles, any 

 organic remains among them ? 



1 1. When a vein comes in contact with a different species of 

 rock from that in which it was first observed, is the vein abruptly 

 cut off, raised, depressed, turned aside, or are its materials altered ? 



12. If a vein is cut off, or sliifted by the interposition of a 

 stratum or mass of rock, does it reappear or recover its direction 

 on the other side of the interposed body? 



13. Is it shifted or cut off without any apparent cause ? 



14. Are neighbouring veins composed of the same materials? 



15. Have veins, consisting of similar materials, the same di- / 

 rection ? 



16. What' proportion do the several veins bear to the rock in 

 which they are found ? 



17. Do they run parallel to each other ? 



18. Do they tend to a common centre ? , 



10. Do they cross each other? and what phaenomena occur 

 under these circumstances ? 



20. What is the nature of their floor, sides, and roof ? 



21. Do the veii.s seem to have produced any change on the 

 adjacent part of the containing rock, as indurating it, disturbing 

 the i-egularity of its stratification, &Cc ? 



21. Can they be traced to beds composed of the same materials 

 as themselves ? 



§ XI. Concerimg Organic Remains. 



1. To what class, and species, do they belong? 

 . 2. Do tlicy conform to the direction of the strata in which 

 they occur ? 



'<j. Do particular shells, &c. affect particular strata ? 



4. What change have they undergone ? Are the vegetables 

 compressed, carbonized, bituminized, silicified, or penetrated 

 with pyrites in whole or in part ? Do the shells retain their 

 enamel ? the bones their phosphoric acid, &c. ? 



5. Do the shells or other organic remains appear perforated 

 or v.'orm-eaten ? 



G. What 



