President's Address. 



195 



wider field of foreign geology ; ever remembering that what 

 is limited and irregular in one district may be continuous 

 and regular in another, and that we are bound always to 

 take the fullest development we can discover as the typical 

 standard of our groups and systems. Let us then abide by 

 this idea of passage beds as a provisional convenience, avoid- 

 ing all sharp demarcations between contiguous systems, be- 

 lieving that nature's operations are incessant and continuous, 

 and that all breaks, whether physical or vital, are at the 

 most but local and limited phenomena. 



Sy sternal Arrangements, — A fourth point to which we 

 would direct attention is the discovery of numerous second- 

 ary coal-fields, and the effects of such discoveries, first, on 

 many cherished theories respecting the conditions of the Car- 

 boniferous era ; and, second^ the chronological arrangement 

 of our secondary formation. The fact that we have import- 

 ant coal-fields of triassic, oolitic, and cretaceous life, like 

 those of Virginia, Brazil, Vancouver's Island, Austria, India, 

 the Indian Archipelago, and Australia, must for ever set 

 aside as untenable all hypotheses of abnormal climates, car- 

 bonic acid atmospheres, and universal conditions for the 

 carboniferous epoch. The fact is, that coal is a product of 

 every age, and that the coal-forming conditions, like other 

 conditions, will vary in intensity according to the geogra- 

 phical arrangement of sea and land, and the consequent 

 climatic influences which such arrangements may induce. 

 Besides, we are far from having proved the strict contem- 

 poraneity of the so-called Palaeozoic coal-fields ; on the con- 

 trary, every new foreign survey raises the gravest doubts on 

 this point, and leads to the belief that these old coal-deposits 

 range throughout the whole cycle embraced by the Devonian, 

 the Carboniferous, and Permian systems of the British Islands. 

 Again, the difficulty which foreign surveyors find in co-ordi- 

 fcating their discoveries with our trias, lias, oolite, and chalk, 

 luggests the idea that the time is not far distant when we 

 must modify the range and nomenclature of these arrange- 

 ments. Be it from America, India, Australia, or New Zea- 

 land, complaints are continually reaching us of the difficulty, 

 or even impossibility, of co-ordinating their strata with those 



vol. m. 2 c 



