Proceedings of the British Association. 367 



a higher order : it merely implied that, having grouped together 

 a set of phenomena, we used the term to represent the state of 

 our knowledge at any moment of time. Such were the laws of 

 the distribution of organic remains ; it was impossible to ascertain 

 all the conditions which involved the appearance of any particu- 

 lar form of life ; and we have never risen, nor can rise, to such 

 laws. With respect to the identification of strata in distant coun- 

 tries by organic remains, in the absence of direct evidence, he 

 considered this evidence was as strong as we could expect to ob- 

 tain ; having proved its correctness in this country, we applied it 

 to more distant tracts. Assuming, in the first instance, a coinci- 

 dence between the conditions and organic types of our own coun- 

 try, and that which we examine, if in this investigation we meet 

 with nothing contradictory, we extend the value of our inductive 

 process. Amongst the lower rocks of that part of America de- 

 scribed, there was a carboniferous and pentremite limestone, an 

 intermediate group, and a Silurian group, all bearing a remarka- 

 ble analogy to those of England. The series as a whole was 

 more calcareous, and therefore we might not expect the same 

 tranchant differences which the alternation of masses of shale 

 and sandstone had produced with us. An illustration of these 

 local differences occurred in the interpolation of the calcareous 

 beds, of which the crumbling colleges of Oxford were built, be- 

 tween the Oxford and Kimmeridge clays of the south of Eng- 

 land. At Cambridge, these clays formed one uninterrupted de- 

 posit of mud, two thousand feet thick. In England, all the work 

 was done ; the long tiresome narrative, like an old chronicle full 

 of enormous detail — like a book, too, some of the leaves were 

 torn out, and others so defaced that no mortal man could read 

 them. To supply this, we looked to other countries ; and be- 

 lieving that nature has no starts, or blanks, seek to supply the 

 deficiencies in our own series, by an examination of those of other 

 countries. In reference to the economical importance of the dis- 

 trict which formed the subject of the memoir, Mr. Sedgwick re- 

 marked, that this country possessed inexhaustible mineral treas- 

 ures, and the finest inland navigation in the world, and pictured 

 the influence it might be expected to exert, in the coming period 

 of time, its effect on the fortunes of the civilized world, when all 

 the intellect of the most active and energetic men on that part of 

 the earth should be brought to bear on these treasures, and he re- 



