RECOMMENDATIONS. 479 



of the non-metalliferous fissures which cross the planes of the 

 strata, and in some instances divide many contiguous strata, 

 should be observed, in relation to the same circumstances in 

 the dykes and mineral veins of the vicinity ; with a view to 

 ascertain whether there be any and what connexion between 

 these phaenomena'. 



*10. That the history of ancient vegetation should be further 

 examined, by prosecuting the researches into the anatomy of 

 fossil wood which have been exemplified in Mr. Witham's re- 

 cent volume. 



11. That the quantity of Mud and Silt contained in the water 

 of the principal rivers of Great Britain should be ascertained, 

 distinguishing, as far as may be possible, the comparative quan- 

 tity of sediment from the water at different depths, in different 

 parts of the current, and at different distances from the mouth 

 of the river ; distinguishing also any differences in the quality 

 of the sediment, and estimating it at different periods of the 

 year ; with a view of explaining the hollowing of valleys, and 

 the formation of strata at the mouths of rivers. 



12. That the experiments of the late Mr. Gregory Watt, on 

 the fusion and slow cooling of large masses of stony substances, 

 should be repeated and extended by those who, from proximity 

 to large furnaces, have an opportunity of trying such experi- 

 ments on a large scale ; and that trial should be made of the 

 eflfect of long-contihued high temperature on rocks containing 

 petrifactions, in defacing or modifying the traces of organic 

 structure, and of the effect of the continued action of steam or 

 of water at a high temperatui-e, in dissolving or altering mine- 

 rals of difficult solution. 



*13. That the dimensions of the bones of extinct animals 

 should be expressed numerically in tables, so as to show the 

 exact relations of their dimensions to those of animals now 

 living ; and also to show what combinations of dimensions in 

 the same animal no longer exist. 



* 14. That the following Geological queries be proposed : 

 1.) Are there any instances of contorted rocks interposed 



between strata not contorted ? 



2.) Is there any instance of secondary rocks being altered in 

 texture or quality by contact with gneiss or primary slates ? 



3.) Is the occurrence of cannel coal generally connected with 

 faults or dislocations of the strata ? 



* Mr. Phillips has undertaken to state the results of his examination on tliis 

 suhject in certain parts of the North of England, and requests to be favoured 

 with communications relating thereto. 



