ADDRESS. J> 



and thereafter by slow cooling could be made to resume a stony texture. 

 Again, Button had asserted that under the vast pressures which must be 

 effective deep within the earth's crust, chemical reactions must be power- 

 fully influenced, and that under such conditions even limestone may 

 conceivably be melted without losing its carbonic acid. Various specious 

 arguments had been adduced against this proposition, but by an ingeni- 

 ously devised series of experiments Hall succeeded in converting lime- 

 stone under great pressure into a kind of marble, and even fused it, and 

 found that it then acted vigorously on other rocks. These admirable 

 researches, which laid the foundations of experimental geology, constitute 

 not the least memorable of the services rendered by the Huttonian school 

 to the progress of science. 



Clear as was the insight and sagacious the inferences of these great 

 masters in regard to the history of the globe, their vision was necessarily 

 limited by the comparatively narrow range of ascertained fact which up 

 to their time had been established. They taught men to recognise that 

 the present world is built of the ruins of an earlier one, and they 

 explained with admirable 'perspicacity the operation of the processes- 

 whereby the degradation and renovation of land are brought about. But 

 they never dreamed that a long and orderly series of such successive 

 destructions and renewals had taken place, and had left their records in 

 the crust of the earth. They never imagined that from these records 

 it would be possible to establish a determinate chronology that could be 

 read everywhere, and applied to the elucidation of the remotest quarter of 

 the globe. It was by the memorable observations and generalisations of 

 William Smith that this vast extension of our knowledge of the past 

 history of the earth became possible. While the Scottish philosophers 

 were building up their theory here. Smith was quietly ascertaining by 

 extended journeys that the stratified rocks of the West of England occur 

 in a definite sequence, and that each well-marked group of them can be 

 discriminated from the others and identified across the country by means 

 of its enclosed organic remains. It is nearly a hundred years since he 

 made known his views, so that by a curious coincidence we may fitly 

 celebrate on this occasion the centenary of William Smith as well as that 

 of James Hutton. No single discovery has ever had a more momentous 

 and far-reaching influence on the progress of a science than that law ot 

 organic succession which Smith established. At first it served merely 

 to determine the order of the stratified rocks of England. But it soon 

 proved to possess a world-wide value, for it was found to furnish the key 

 to the structure of the whole stratified crust of the earth. It showed that 



