THE GROWTH OF SCIENCE IN THE NINETEENTH CENTURY. 169 



called, the exact and proved knowledge of the successive phases of the 

 world's life, maj^ be said to date from the closing years of the eight- 

 eenth century. 



In 1783 James Hutton put forward in a brief memoir his Theory of 

 the Earth, which, in 1795, two years before his death, he expanded into 

 a book; but his ideas failed to lay hold of men's minds until the cen- 

 tury had passed away, when, in 1802, they found an able expositor in 

 John Playfair. The very same year that Hutton puljlished his theory, 

 Cuvier came to Paris and almost forthwith began, with Brongniart. his 

 immortal researches into the fossils of Paris and its neighborhood. And 

 four years later, in the year 1799 itself, William Smith's tabulai- list 

 of strata and fossils saw the light. It is, I believe, not too much to 

 say that out of these geology, as we now know it, sprang. It was 

 thus in the closing years of the eighteenth century that was begun the 

 work which the nineteenth century has carried forward to such great 

 results, but at this time onl}^ the select few had grasped the truth, and 

 even the}^ only the begimiing of it. Outside a narrow circle the 

 thoughts even of the educated about the history of the globe were 

 bounded by the story of the deluge — though the story was often told 

 in a strange fashion — or were guided by fantastic views of the plastic 

 forces of a sportive nature. 



In another branch of science, in that which deals with the problems 

 presented by living beings, the thoughts of men in 1799 were also very 

 different from the thoughts of men to-da3^ It is a very old quest, the 

 quest after the knowledge of the nature of living beings, one of the 

 earliest on which man set out; for it promised to lead him to a knowl- 

 edge of himself, a promise which perhaps is still l)efore us, but the 

 fulfillment of which is yet far oft'. As time has gone on. the pursuit 

 of natural knowledge has seemed to lead man away from himself into 

 the furthermost parts of the universe, and into secret workings of 

 Nature in which he appears to be of little or no account; and his 

 knowledge of the nature of living things, and so of his own nature, has 

 advanced slowly, waiting till the progress of other branches of natural 

 knowledge can bring it aid. Yet in the past hundred years the bio- 

 logic sciences, as we now call them, have marched rapidly onward. 

 . We may look upon a living body as a machine doing work in accord- 

 ance with certain laws, and may seek to trace out the working of the 

 inner wheels, how these raise up the lifeless dust into living matter, 

 and let the living matter fall away again into dust, giving out move- 

 ment and heat. Or we may look upon the individual life as a link in 

 a long chain, joining something which went ])efore to something about 

 to come, a chain whose l)eginning lies hid in the farthest psist, and may 

 seek to know the ties which ))ind one life to another. As we call up 

 to view the long series of living forms, living now or flitting like 

 shadows on the screen of the past, we ma}' strive to lay hold of the 



