System cannot be oftlie age of the Old Red Sandstone. 121 



which lived on it would previously shift their habitat to other 

 submarine abodes, where they may have existed into higher 

 epochs, and thereby mislead the geologist of after days to con- 

 fidently identify, as mountain limestone for instance, rocks 

 which in reality are ot the age of the New Red Sandstone, — a 

 perplexing occurrence, which can only be effectually cured by 

 supposing an universal annihilation of animal and (it would 

 be very convenient to include) vegetable life, and a creation 

 of entirely new genera and species, of both ; otherwise the 

 oolite fossils of India, again, which have been so cautiously re- 

 ported by Col. Sykes, and so triumphantly appealed to by 

 Mr. Lonsdale, may be of the age of the European terliaries. 

 Devonian and Silurian fossils, like those discovered by Mr. 

 Lyell, may be found above, below, or in the American coal- 

 measures ; and many other antipodal equivalents might be 

 very seriously deranged. 



The assumption that the Cambrian rocks are the true base 

 line of geology as a system, is, however, altogether gratuitous ; 

 it appears to have been founded on the supposed paucity of 

 their organic contents, their mineral aspect and character, and 

 because in the region where they occur, they are the nether- 

 most in a descending section from the New Red Sandstone : 

 they do however contain organic remains, which Professor 

 Sedgwick states to be Silurian species, so that, by the way, 

 one System would have served instead of two. The number 

 of species, or the greater or less abundance of individuals, I 

 take to be altogether a matter of accident quite independent 

 of age or time. A large area of Cornwall, bounded by about 

 the meridian of St. Austell and the parallel of Padstow, is 

 equally if not more destitute of them. Chemical analysis con- 

 firms the evidence afforded by the presence of organic re- 

 mains, that they are of derivative origin, regenerated from the 

 destruction (not by abrasion) of pre-existing rocks ; they have 

 no pretensions to be classed with those primitive or primary 

 slates, 



" which rose from out the trackless sea, 



Those slates for boys to scrawl, when boys should be." 



The Cambrian slates are not simple minerals, or compounds 

 of simple minerals, which have been governed by the laws of 

 definite proportions, but plain secondary aggregates of varvintr 

 per-centages, of commonly eight or ten constituents; they are 

 parted from the Old Red Sandstone by only 7500 feet of strata 

 whicli graduate into them, and togAlier with the Silurian prefer 

 far better pretensions to be admitted into the Old Red Sand- 

 stone system, than any of the vast group of Devon and Corn- 

 wall. 



