NATURAL SCIENCE IN THE NINETEENTH CENTURY 383 



evidence as has been advanced of its ordinary and frequent 

 occurrence under such natural conditions as prevail to-day. 



PROGRESS OF GEOLOGICAL SCIENCE. In 1785 Hutton, to 

 whom we have already briefly referred, presented to the Royal 

 Society of Edinburgh a paper entitled Theory of the Earth, or 

 an Investigation of the Laws Observable in the Composition, 

 Dissolution and Restoration of Land upon the Globe (p. 317). 



In this remarkable work the doctrine is expounded that geology 

 is not cosmogony, but must confine itself to the study of the materials 

 of the earth ; that everywhere evidence may be seen that the present 

 rocks of the earth's surface have been formed out of the waste of 

 older rocks . . . that every portion of the upraised land is subject 

 to decay ; and that this decay must tend to advance until the whole 

 of the land has been worn away. ... In some of these broad general- 

 izations Hutton was anticipated by the Italian geologists; but to 

 him belongs the credit of having first perceived their mutual relations 

 and combined them in a luminous coherent theory everywhere based 

 upon observation. ... It is by his Theory of the Earth that Hutton 

 will be remembered with reverence while geology continues to be 

 cultivated. Geikie. 



In the early part of the nineteenth century it was, nevertheless, 

 firmly held that the earth had undergone various "revolutions," 

 "catastrophes" and the like which, taken together with the Flood 

 of Noah, were sufficient to explain its present surface features, such 

 as mountains, valleys, plains, boulders, caves, deserts, sea-coasts, etc. 

 These views were summed up in the term Catastrophism, i.e. that 



at a number of successive epochs of which the age of Noah was 

 the latest great revolutions had taken place on the earth's surface ; 

 that during each of these cataclysms all living things were destroyed ; 

 and that, after an interval, the world was restocked with fresh assem- 

 blages of plants and animals, to be destroyed in turn and entombed 

 in the strata at the next revolution. Judd. 



Moreover, at the beginning of the century most considerations 

 of the earth and of the living world were dominated by two pre- 

 conceived ideas : first, that the universe, including the earth and 

 its belongings, had originated as described in the first chapter of 



