﻿Yol. 64.] ANNIYERSAEY ADDEESS OF THE PEESIDENT. cix 



which contained the first account of the employment of the micro- 

 scope for the elucidation of the structure of a group of English 

 igneous rocks, and in which the essential identity of structure 

 and composition between ancient and modern lavas was maintained. 

 He followed up this memoir with others of great value, wherein 

 he described the characters of ancient devitrified pitchstones and 

 perlites,^ and traced the nature of the metamorphism that has been 

 induced around the granite of Land's End.^ John Arthur Phillips 

 now entered the gradually increasing ranks of British modern 

 petrographers, and from 1875 till 1882 continued to contribute to 

 the Quarterly Journal a series of excellent papers, containing the 

 results of his chemical and microscopic analyses of the igneous 

 rocks of the south-western counties and of North Wales. ^ From 

 these crystalline masses he turned to the investigation of clastic 

 materials. His essays on grits and sandstones* and on the red 

 sands of the Arabian Desert ^ gave promise of how much he might 

 have accomplished in the study of sedimentary formations had his 

 health and life been prolonged. 



Among the other observers who now appeared in quick succession 

 as exponents of the new petrography in its application to the rocks 

 of this country, J. Clifton Ward and Erank Eutley may be mentioned 

 as having both begun their communications on the subject to the 

 Geological Society in 1875. Prof. Bonney, about the same time, 

 started the long succession of his petrographical papers which 

 for so many years have appeared in the Quarterly Journal. 

 Ranging over a great variety of rocks, not only of the British Isles, 

 but from many other parts of the world, his papers rise from mere 

 mineralogical details into broader questions of the origin or age of 

 rocks and of mountain-structure. Those which deal with the Alps, 

 based as they are, not only on repeated personal examination of the 

 ground, but on the careful study of microscopic preparations of 

 the rocks of the chain, will always remain as a monument of his 

 unwearied enthusiasm in the cause of our science. He has not only 

 been himself a prolific author, but he has inspired a school of 

 followers who have done signal service in raising petrography from 

 its former neglected condition amongst us to the important position 

 which it now holds in this country. It would be invidious to single 

 out from these still living and active followers any for special notice 



1 Q. J. xxxiii (1877) 449. 2 q. j, ^^^[[ (I876) 407. 



3 Q. J. xxxi, 319 ; xxxiii, 423 ; xxxiv, 471 ; xxxv, 490 ; xxxvi, 1. 



* Q. J. xxxvii (1881) 6. 5 Q^ j^ xj^x^iii (1382) no. 



