150 Sir A. Geikie — Lamarck and Play fair — 



his " Hydrogeologie " be pauses to dwell on this great fact of 

 terrestrial history. "To Nature," he remarks, "time is nothing and 

 is never a difficulty. She always has it at her disposal as a means 

 without limit for the accomplishment of the greatest as well as of 

 the least of her labours" (p. 67). "From the evidence furnished 

 by the earth's crust and by the mass of the mountains, the antiquity 

 of this globe is seen to be so vast as to be absolutely beyond the 

 power of man to appreciate" (p. 88). "Yet how much will this 

 antiquity seem to increase in man's eyes when he shall have been 

 able to form a true idea of the origin of living bodies, as well as of 

 the gradual development and perfection of these bodies ; and, above 

 all, when he shall recognise that lapse of time and the necessary 

 conditions having been required to bring into existence all th& 

 living species which are now to be seen, he is himself the final 

 result and present maximum of this development, of which the 

 ultimate limit, if such should exist, can never be known " (p. 89). 



Another essential principle of geology was recognised by Lamarck 

 perhaps more clearly than bj' any of his pi'edecessors since the time 

 of Aristotle — the principle of constant change upon the surface of 

 the earth. The limited range of knowledge then available on this 

 subject prevented him, indeed, from forming any adequate conception 

 of one great side of it. He did not recognise that besides the various 

 agents that take their origin and do their work on the surface of the 

 earth, there is another powerful source of energy lodged within the 

 interior and manifesting itself from time to time by slow or by 

 sudden movements that more or less change the face of the globe. 

 He writes, indeed, of local catastrophes and of the elevations, 

 subsidences, and heapings-up of material which may now and then 

 result from volcanoes and earthquakes (pp. 83, 97), but that h© 

 could have had no adequate conception of the probable condition of 

 the earth's interior and of its reaction on the surface maj' be inferred 

 from his still accepting the ancient error that all volcanoes on the 

 earth derive their heat and energy from the combustion of seams of 

 coal and other inflammable materials buried within the crust of the 

 earth (p. 111). Nor does he appear to have had any notion of the 

 natural operations whereby land is elevated and mountain-chains are 

 upheaved, for he explained these phenomena by a hypothesis which 

 was hardly less extravagant than some of his speculations in physics 

 and chemistry. Thus he held that the ocean-basins have been 

 scoured out of the surface of the globe by the erosive action of the 

 sea, which, in virtue of its tidal oscillation and westward movement, 

 attacks the eastern coasts of the continents, and throws up its detritus- 

 on their western shores. He thought that in this way the vast 

 hollow that holds the oceanic waters actuallj' travels round the globe, 

 and has done so completely more than once in the earth's history, 

 each revolution requiring a period of nine hundred millions of years 

 for its accomplishment (pp. 178, 260). 



When he contemplated the progress of the changes that take 

 place upon the surface of the earth Lamarck stood on firmer ground, 

 for he drew his conclusions more from the foots of observation than- 



