ai8 EIGHTEENTH CENTURY. PT. HI. 



Hutton teaches that it is by the Study of Changes 

 going on now that we can alone learn the History of the 

 Past. While these discussions were going on upon the 

 Continent, a Scotchman was setting to work in the right 

 way to settle the question. This man was Dr. Hutton, 

 one of the greatest geologists that has ever lived ; and the 

 reason of his greatness was the same which we have found at 

 every step in our history of science. Before he made any 

 theory he sought out the facts. He travelled and observed 

 for himself, he collected patiently details about the layers or 

 strata in the formations of all countries through which he 

 passed ; and it was only after all these investigations that in 

 1788, when he was sixty years of age, he wrote his famous 

 ' Theory of the Earth,' in which he showed how the history 

 of the earth's crust might be traced out. This work, al- 

 though very interesting, was not much read ; but one of 

 Button's favourite pupils, the celebrated Dr. Playfair, wrote 

 a book called * Illustrations of the Huttonian Theory,' by 

 means of which Hutton's opinions became well known. 



About Hutton himself there is very little to tell. He was 

 born in Edinburgh in 1726, studied medicine, and took his 

 doctor's degree in Leyden in 1749, and then returned to 

 Edinburgh, and devoted all his life to science. Of his 

 teaching I should like to write a great deal, but we must 

 content ourselves with a little which can be easily under- 

 stood. His great principle was that it was useless to try and 

 guess how the rocks had been made and fossils buried in 

 them, for this had only led to endless confusion and dis- 

 putes. Men must go, he said, and see with their own eyes 

 how different strata are being formed now, how rivers and 

 glaciers are carrying down earth and stones from the moun- 

 tains into the sea, and how volcanoes are throwing out 

 melted matter which cools down into hard rock ; and then 



