ADDRESS. 7 



clearest light the whole philosophy of Hntton regarding the history of 

 the earth, and enforced it with a wealth of reasoning and copionsnesa 

 of illustration which obtained for it a wide appreciation. From long 

 converse with Hutton, and from profound reflection himself, Playfair 

 gained such a comprehension of the whole subject that, discarding the 

 non-essential parts of his master's teaching, he was able to give so lucid 

 and accurate an exposition of the general scheme of Nature's operations 

 on the surface of the globe, that with only slight corrections and expan- 

 sions his treatise may serve as a text-book to-day. In some respects, 

 indeed, his volume was long in advance of its time. Only, for example, 

 within the present generation has the truth of his teaching in regard to 

 the origin of valleys been generally admitted. 



Various causes contributed to retard the progress of the Huttoniau 

 doctrines. Especially potent was the influence of the teaching of "Werner, 

 who, though he perceived that a definite order of sequence could be 

 recognised among the materials of the earth's crust, had formed singularly 

 narrow conceptions of the great processes whereby that crust has been 

 built up. His enthusiasm, however, fired his disciples with the zeal of 

 proselytes, and they spread themselves over Europe to preach everywhere 

 the artificial system which they had learnt in Saxony. By a curious fate 

 Edinburgh became one of the great headquarters of Wernerism. The 

 friends and followers of Hutton found themselves attacked in their own 

 city by zealots who, proud of superior mineralogical acquirements, turned 

 their most cherished ideas upside down and assailed them in the uncouth 

 jargon of Freiberg. Inasmuch as subterranean heat had been invoked 

 by Hutton as a force largely instrumental in consolidating and upheaving 

 the ancient sediments that now form so great a part of the dry land, his 

 followers were nicknamed Plutonists. On the other hand, as the agency 

 of water was almost alone admitted by Werner, who believed the rocks 

 of the earth's crust to have been chiefly chemical precipitates from a 

 primeval universal ocean, those who adopted his views received the 

 equally descriptive name of Neptunists. The battle of these two con- 

 tending schools raged fiercely here for some years, and though mainly 

 from the youth, zeal, and energy of Jameson, and the influence which his 

 position as Professor in the University gave him, the "Wernerian doctrines 

 continued to hold their place, they were eventually abandoned even by 

 Jameson himself, and the debt due to the memory of Hutton and 

 Playfair was tardily acknowledged. 



The pursuits and the quarrels of philosophers have from early times 

 been a favourite subject of merriment to the outside world. Such a feud 



