TRANSACTIONS Ol' THE SECTIONS. 47 



The numbers iu the first cohiiuu were obtained by taking the specific gravity at 

 lo° before and after removing tlie tannin, and obtaining the percentage equivalent 

 frorn^ Hammer's Table. The third coliimu was found by evaporating 25 cubic 

 centims. in a platinum dish before aud after the removal of the tannin^ and drying 

 the residue for three or four hours at 100°. 



For fiu'ther details the reader is referred to a memoir by Miintz and Ramspacher 

 in the 'Ann. Chim. Phys.' 1875 [5], v. 



GEOLOaT. 



Address hi/ Thomas Wiught, M.D., F.R.S.E., F.G.S., President of the 



Section. 



In taking this Chair today, I desire first to express my deep sense of gratitude to 

 the Council of the British Association for the honour conferred on me, and, secondly, 

 to say how much I feel the responsibility of the position iu which I am placed 

 when I recollect the long list of distinguished sacans who in former years have 

 presided over this Section. The fact that Buckland, Conybeare, De la Beche, Forbes, 

 Geikie, Hopkins, Jukes, Lyell, Murchison, Phillips, Eamsay, and other men illus- 

 trious in the annals of British Geology have filled this chair, may well make mo 

 doubt how far my own feeble powers are equal to an efficient discharge of its duties ; 

 however, I shall bring a willing mind and an honest determination to do my best 

 on this occasion. 



We have met again in one of the most interesting centres iu England to all 

 students of practical geology ; for within a short distance of this spot we can 

 examine some of the most instructive sections of Palaeozoic aud Mesozoic rocks, 

 and study a magnificent collection of local fossils obtained from them. So I pui-pose 

 occupying the short space of time allowed for this introductory address in attempt- 

 ing to give you a general outline of the geological character of the country around 

 Bristol, willi a resume of some of its more remarkable Palceontological features, by 

 way of inducing you to visit and study the admirable collection of local organic 

 remains so well displayed in the Museum of the Bristol Philosophical Institution. 



Geology is the history of the Earth ; for it attempts to construct a table of pheno- 

 mena, physical and chemical, organic aud inorganic, which have succeeded each 

 other from the past to the present, and on the terrestrial surface traces of its origin 

 and progTess are preserved. 



That phase which we see today is only the most recent of its eventful history, 

 and although the last, is not the final one, as the physical forces that are ever in 

 action among its diiiereut parts are slowly and steadily producing new combina- 

 tions, which in time will effect mutations in its structure, change its physiogi'aphy, 

 and remodel the whole. 



There is probably no other' place in England where, within so limited an area, 

 typical examples of so many different formations occur as around this city : for 

 within a short distance by road or rail we may investigate the Silurian, Devonian, 

 Carboniferous, Triassic, Liassic, Oolitic, and Cretaceous formations^ all of which 

 will yield many interesting species for the cabinet of the palreontologist, and a 

 valuable series of rocks and minerals for the student of Physical Geology. 



These diflPerent fonnations in relation to the entire series of stratified rocks will 

 be better understood by a reference to the following Table, in which the periods, 

 divisions, formations, and typical localities are given : — 



