350 THE CANADIAN NATURALIST. [Oct 



Silurian rocks extend have, I repeat, been long harried, with an 

 intense desire -on the part of many searchers to find something 

 which would gainsay the datum-line that marks the beginning of 

 vertebrated life; and, as all these efforts have failed, I have some 

 right to insist upon the value of such a vast amount of what those 

 who seek to oppose this view still persist in calling negative evi- 

 dence. The facts however remain, and on them I rest my belief. 



In this short introductory address I cannot attempt to present 

 to you a sketch of the general recent progress of geological 

 science in other parts of Europe or in America. This must be 

 sought in the well-digested recent address of the actual President 

 of the Geological Society, Mr. W. J. Hamilton. I must, for the 

 most part, confine my observations to certain British questions, 

 the more so as I know that our distinguished associates of other 

 countries, who honor us by their presence on this occasion, come 

 to us mainly for the purpose of ascertaining the progress we have 

 made in our isles, and also with the view of visiting those of our 

 typical localities of which they have read. 



Among those visitors from abroad, I must first allude to my 

 eminent friend, M. Henri von Dechen, the director of the mines of 

 Prussia. In speaking of him, I turn back to the year 1827 (four 

 years before the foundation of the British Association), when he 

 and his associate Oeynhausen explored our islands, and when it 

 was the good fortune of Professor Sedgwick and myself to examine 

 parts of the Highlands of Scotland in company with those able 

 young German geologists, who have since risen to such high dis- 

 tinction. Of him who is now present, I will only say that the 

 great geological map of the Rhine Provinces, of which he has 

 been the director, is a work of special value to English geologists. 

 In this map are delineated with precision the whole series of the 

 Palaeozoic rocks on both banks of the Rhine, from those Devonian 

 limestones of the Eifel which were correlated with our own by 

 Sedgwick and myself, to the Coal-measures and the several Ter- 

 tiary and superficial deposits, as well as all the rocks of igneous 

 origin ; in it are also elaborated in the most skilful manner all the 

 numerous intermediate strata, of Devonian and Mountain-lime- 

 stone age, which are wanting in the immediate vicinity of Bir- 

 mingham, but which have to a great extent their equivalent re- 

 presentatives in other parts of our islands. Whilst for the subor- 

 dinate strata thus delineated M. von Dechen and all Prussian 

 geologists naturally employ local names, I am glad to find that the 



