ADDRESS. 



Ixv 



called, I hope not too grandiloquently, the Oxford School of Geology, — have, 

 if I may judge of others by myself, been often distanced in the race, and 

 when they endeavoured to make good their lost ground, found themselves 

 transported into a new, and to them an almost unknown region. 



Thus the thorough exploration which has taken place of the Silurian and 

 Cambrian systems, through the exertions of two of our oldest and most 

 valued Associates, has added a new province — ought I not rather to say, a 

 new kingdom ? — to the domain of Geology, and has carried back the records of 

 the creation to a period previously as much unknown to us as were the annals 

 of the Assyrian dynasties before the discoveries of Sir Henry Rawlinson. 



I might also be disposed to claim for the recent investigations of Botanists 

 some share in fixing the relative antiquity of particular portions of the globe, 

 for, from the floras they have given us of different islands in the Great Pacific, 

 it would appear, that the families of plants which characterize some groups 

 are of a more complicated organization than those of another. Thus whilst 

 Otaheite chiefly contains Orchids, Apocynese, Asclepiadeae and Urticeae ; the 

 Sandwich.Islands possess LobeliacPEe and Goodenoviae ; and the Galapagos 

 Islands, New Zealand and Juan Fernandez, Compositas, the highest form 

 perhaps of dicotyledonous plants. 



In deducing this consequence, however, I am proceeding upon a principle 

 which has lately met with opposition, although it was formerly regarded as 

 one of the axioms in geology. 



Amongst these, indeed, there was none which a few years ago seemed so 

 little likely to be disputed, as that the classes of animals and vegetables which 

 possessed the most complicated structure were preceded by others of a more 

 simple one ; and that when we traced back the succession of beings to the 

 lowest and the earliest of the sedimentary formations, we arrived at length 

 at a class of rocks, the deposition of which must be inferred, from the 

 almost entire absence of organic remains, to have followed very soon after 

 the first dawn of creation. But the recognition of the footsteps and remains 

 of reptiles in beds of an earlier date than was before assigned to them, 

 tended to corroborate the inferences vvhich had been previously deduced 

 from the discovery, in a few rare instances, in rocks of the secondary age, of 

 mammalian remains ; and thus has induced certain eminent geologists boldly 

 to dispute, whether from the earliest to the latest period of the earth's history 

 any gradation of beings can in reality be detected. 



Into this controversy I shall only enter at present, so far as to point out 

 an easy method of determining the fact, that organic remains never can 

 have existed in a particular rock, even although it may have been subjected 

 to such metamorphic action as would have obliterated all traces of their pre- 

 sence. This is simply to ascertain, that the material in question is utterly 

 destitute of phosphoric acid ; for inasmuch as every form of life appears to 

 be essentially associated with this principle, and as no amount of heat would 

 be sufficient to dissipate it when in a state of combination, whatever quantity 

 of phosphoric acid had in this manner been introduced into the rock, rau^ 

 have continued there till the end of time, notwithstanding any igneous ope- 

 rations which the materials might have afterwards undergone. But as the 

 discovery of very minute traces of phosphoric acid, when mixed with the 

 other ingredients of a rock, is a problem of uo small difficulty, an indirect 

 method of ascertaining its presence suggested itself to me in some experi- 

 ments of the kind which I have instituted, namel}', that of sowing some kind 

 of seed, such for instance as barley, in a sample of the pulverized rock, and 

 determining whether the crop obtained yielded more phosphoric acid than 



1856. e 



