ADDRESS BY MR. MURCHISON. xliu 



on Dimorphism, printed in this volume, which gives a fuller statement 

 than we before possessed, of the facts arrived at by foreign experi- 

 menters, the reasonings founded upon them, and the questions which 

 are left for future inquirers to solve. This is the precise point at 

 which the Association aims in the reports on the state of our know- 

 ledge, which occupy the chief space in its publications ; they are not 

 intended, like the articles in an encyclopaedia, to teach and diffuse 

 science, but to advance it — to show what has been done, with a specific 

 view to what there remains to do — to look forward to conquests to 

 come, rather than backward on those which are past — to survey the 

 border territory, and reconnoitre the debateable land. We have in 

 this, as in other respects, followed in the steps of him who gave the 

 original sketch of .an Institution like the present. The great teacher 

 of inductive science and experimental philosophy, who first showed 

 the importance of knowing the lines which divide knowledge from 

 ignorance, and in the memorable list of desiderata which he drew 

 up, did more for "the progression of the sciences" than Would have 

 been done by anj' discoveries he could have made. 



Having thus endeavoured to elucidate, by reference to some portions 

 of its recent transactions, the comjarehensive system of this Association, 

 and to mark the real value of its corporate influence, its pecuniary re- 

 sources, and its concentrated intelligence, I would lastly notice that 

 part of the system which has given occasion to our present muster in 

 this prosperous and splendid city — the migratory character of our 

 meetings. In these migrations there is a double advantage ; the As- 

 sociation gains much by them, and perhaps the places it visits do not 

 gain less ; for its visits may sometimes have the effect of drawing 

 genius from obscuritj', and giving an impulse to powers which might 

 never have been exerted, and a direction to labours which might 

 otherwise have been misapplied. To our own body two great advan- 

 tages are derived : one is, that the wave, in rolling along, gathers to it 

 all the scattered science of the land, and that a more general and 

 powerful union is thus formed than could ever be collected by an 

 Institution resting on a fixed point : the second is, that varied objects 

 of interest and different opportunities of utility are offered by circum- 

 stances proper to the different places which the Association visits; 

 thus the lofty tower of York furnished means for the best experiments 

 that have been made on the phenomena of rain ; Liverpool contributed 

 its contingent to our knowledge of the tides ; whilst Bristol carried a 

 line from sea to sea, to ascertain the permanence or the mutations of 

 the level of the land and water. And does not this city and vicinity, 

 Gentlemen, also present its own peculiar objects of speculation and 

 opportunities of research? Is not the optical philosopher interested 

 in its celebrated glass-works? Can the chemist contemplate with 



