32 Anniversary Address of the 



ous acid were formed at the surface in the older times, and 

 he has even had the courage to present us with a diagram of 

 Chaos, entitled " Chaos primitif," representing a scene by no 

 means rude and disorderly, but where we behold two pyra- 

 midal mountains, from one of which the ordinary volcanic 

 lavas and more volatile substances, such as sulphur, chlorine 

 and aqueous vapour, are evolved ; while from the summit of 

 the other, granitic compounds, tin, fluor, and the more refrac- 

 tory and less volatile materials, are discharged.* It is sug- 

 gested that the greater part of the metals which usually 

 accompany tin were concentrated in the first envelope of the 

 globe, but after the palaeozoic epoch they were withdrawn 

 from circulation, and like the primitive granites ceased to be 

 emitted from the interior. The gases and vapours, from which 

 the more ancient metalliferous compounds were sublimed, 

 would, it is said, have been most deleterious to organic beings 

 living in the air and ocean, so that their evolution in the sea 

 and atmosphere in later times was discontinued. 



For my own part, after having given the most patient con- 

 sideration to these views, I see no sufl&cient grounds for 

 believing that the same granitiform mixtures and metalli- 

 ferous emanations may not have been disengaged in equal 

 quantity at every successive geological period down to the 

 most modern. We are taught by the activity of several 

 hundred volcanoes, that there must now be lakes and seas of 

 melted matter in the interior of the earth, in every state, 

 from one of perfect fusion to one of incipient crystallization ; 

 and as solid rock must thus frequently originate in great 

 masses, under conditions different from that of lava poured 

 out into the atmosphere, why should we not adopt as the 

 most probable conjecture the idea that this matter is now, as 

 of old, passing into granite, or into some of the granitiform 

 compounds, more especially when we know that silex abounds 

 in many modern lavas, and that certain obsidians and pumice 

 do not differ materially in their component elements from 

 granite. 



I fully assent to the doctrine so ably advocated by M. E. 



* Bulletin, 2d Series, vol. iv. p. 1322. 



