A HALF-CENTURY OF SCIENCE. 219 



found it impossible to refer. Such for instance are, in biology alone, 

 Owen's memorable report on the homologies of the vertebrate skeleton ; 

 Carpenter's laborious researches on the microscopic structure of shells ; 

 the reports on marine zoology by Allman, Forbes, Jeffreys, Spence 

 Bate, Norman, and others ; on Kent's Cavern by Pengelly ; those by 

 Duncan on corals ; Woodward on crustacese ; Carruthers, Williamson, 

 and others on fossil botany, and many more. Indeed, no one who has 

 not had occasion to study the progress of science throughout its vari- 

 ous departments can have any idea how enormous how unprecedent- 

 ed the advance has been. 



Though it is difficult, indeed impossible, to measure exactly the ex- 

 tent of the influence exercised by this Association, no one can doubt 

 that it has been very considerable. For my own part, I must acknowl- 

 edge with gratitude how much the interest of my life has been en- 

 hanced by the stimulus of our meetings, by the lectures and memoirs 

 to which I have had the advantage of listening, and, above all, by the 

 many friendships which I owe to this Association. 



Summing up the principal results which have been attained in the 

 last half-century we may mention (over and above the accumulation of 

 facts) the theory of evolution, the antiquity of man, and the far great- 

 er antiquity of the world itself ; the correlation of physical force and 

 the conservation of energy ; spectrum analysis and its application to 

 celestial physics ; the higher algebra and the modern geometry ; lastly, 

 the innumerable applications of science to practical life as, for in- 

 stance, in photography, the locomotive-engine, the electric telegraph, 

 the spectroscope, and most recently the electric light and the telephone. 



To science again we- owe the idea of progress. The ancients, says 

 Bagehot, " had no conception of progress ; they did not so much as 

 reject the idea ; they did not even entertain it." It is not, I think, 

 now going too far to say that the true test of the civilization of a na- 

 tion must be measured by its progress in science. It is often said, how- 

 ever, that great and unexpected as the recent discoveries have been, 

 there are certain ultimate problems which must ever remain unsolved. 

 For my part, I would prefer to abstain from laying down any such 

 limitations. When Park asked the Arabs what became of the sun at 

 night, and whether the sun was always the same, or new each day, 

 they replied that such a question was childish, and entirely beyond the 

 reach of human investigation. I have already mentioned that, even as 

 lately as 1842, so high an authority as Comte treated as obviously im- 

 possible and hopeless any attempt to determine the chemical comj)osi- 

 tion of the heavenly bodies. Doubtless there are questions, the solu- 

 tion of which we do not as yet see our way even to attempt ; never- 

 theless the experience of the past warns us not to limit the possibilities 

 of the future. 



But, however this may be, though the progress made has been so 

 rapid, and though no similar period in the world's history has been 



