Montagna — The Metamorphism of Rocks. 359 



employment of William Smith by the Bath Town Council, on the 

 failure of the supply in the hot springs in 1812. As early as 1808, 

 a minute relating to this subject may be seen in the Corporation 

 books. 



The connection of Wm. Smith with Bath during the development 

 of his geological ideas is thus summarized. 



The examination of the district between High Littleton and Bath 

 first led him to suppose a regularity in the succession of all the 

 strata : the planning of the Somersetshire Coal Canal near Bath 

 was the cause of the tour through England which enabled him 

 to confirm his supposition : the difficulty in distinguishing " the 

 Oolitic rocks on and near the end of the canal towards Bath" led 

 him to " the discovery of a mode of identifying the strata by the 

 organized fossils respectively imbedded therein." 



The _^rs^ collection of fossils stratigraphically arranged was made 

 by him at Cottage Crescent, Bath. 



The first table of the order of the strata was drawn up by him at 

 Pulteney Street, Bath. 



The first geological map known is his map of the district of Bath. 



The first geological map of England was coloured by him while 

 living near Bath. 



The first announcement of the publication of a geological map of 

 England, was his " prospectus" dated from Midford, Bath. 



The first introduction of his discovery to public notice was 

 through the friends he made in Bath. 



II. — The Metamorphism of Eocks. 



By the Chevalier Crescenzo Montagna. 



[Nouvelle Theorie du Metaraorphisme des Roches fondee sur les phenom^nes de 

 fossilisation des Animaux et des Plantes de tous les Ages Geologiques. 3 Plates. 

 Naples, 1869. pp.127. London: Trubner and Co.] 



^inHE term Metamorphic is usually applied to rocks whose original 

 \_ structure has been obscured. Contact with igneous rocks in a 

 molten state was first taught by Hutton, and has been generally 

 accepted as the principal cause. 



But there are many forces, both chemical and physical, which 

 tend to produce change in rocks, and it has been well said that all 

 rocks are in a metamorphic condition, since all have suffered some 

 changes subsequent to their formation, and changes they are con- 

 tinually undergoing. Professor Montagna takes this comprehensive 

 view of the subject, and regards all rocks as metamorphic. 



Allowing the means and causes which continually modify the 

 crust of the earth to have been always the same, he considers the 

 difference in rocks of similar origin to result in general from a 

 longer series of metamorphic actions. Erom Tertiar}^ strata down- 

 wards there are metamorphoses more or less profound ; and the 

 author discusses these changes from the evidence furnished by the 

 fossil remains, whether of plants or animals. This mode of treating 

 the subject he considers more positive than if the e^T.dence were 



