﻿ex PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May I908, 



here ; but I feel sure that the Society will permit me to name one 

 who may be regarded as the type and leader among them, and who 

 has long since gained our esteem and our admiration. Dr. Teall 

 from the time when, in 1884, he contributed his paper on the 

 dykes in the North of England has continually enriched the petro- 

 graphical literature of this country. His separate volume on 

 ' British Petrography,' published in 1888, which will long remain 

 the standard treatise on the subject, probably did more than any 

 other work to gain from foreign geologists an appreciation of the 

 high place to which the study of rocks has at last attained in the 

 country of Sorby. ISTot by any means the least important feature 

 in the Society's Quarterly Journal for the last twenty years has 

 been the number and excellence of the petrographical papers. The 

 names of Profs. Judd, Cole, and Watts, of Mr. Harker, the late 

 General McMahon, Dr. Arnold-Bemrose, Miss Eaisin, and others 

 will^always be associated with the great petrographical revival of 

 the nineteenth century in Britain. 



Naturally this renewed interest in the study of the rocks of the 

 country has been mainly directed to the crystalline masses. Our 

 volcanic rocks of all ages from the pre-Cambrian to the Tertiary 

 series have been diligently studied, and our knowledge of them now 

 stands in amazing contrast to our ignorance thirty years ago. The 

 schists and other metamorphic rocks have likewise been made the 

 subjects of prolonged examination, and have had a flood of new light 

 thrown upon their origin and history, though they still bristle with 

 difficulties. But the sedimentary formations, offering perhaps less 

 obvious attraction, have remained comparatively neglected. Yet it 

 was^'with calcareous grits, limestones, and marls that Dr. Sorby 

 began the series of expositions with which he tried to awaken his 

 brother-geologists to the value of the microscope as an adjunct to 

 other instruments of geological research. It was to sedimentary 

 rocks, too, that he devoted the two suggestive addresses which he 

 gave to the Society during his Presidency in 1879 and 1880. In 

 spite of his example, however, we have had but few communications 

 on this branch of petrography. I have already referred to the papers 

 by J. A. Phillips. Mr. Wethered has given us a series of descriptions 

 of Silurian, Devonian, and Jurassic limestones. Dr. Teall also, in 

 his Presidential address in 1902, dealt with the petrography of the 

 sedimentary rocks. Mr. Thomas has discussed the mineralogical 

 constitution of the finer material of the Bunter pebble-beds in the 

 West 'of England. But there can be no doubt that much still 



