434 



NINETEENTH CENTURY. PT. HI. 



The work of the sixteenth century, as we saw (p. 82), 

 was to overcome that blind worship of authority which had 

 sprung up during the Dark Ages, and which is the greatest 

 enemy to true knowledge. 



In the seventeenth century the march of scientific 

 discovery began with Galileo, and advanced slowly but 

 triumphantly through many dangers and difficulties, till 

 it ended in the grand generalizations of Newton. This 

 was the first great era of modern science, especially of 

 astronomy and physics, though biology also made a great 

 stride when Harvey demonstrated the circulation of the 

 blood. 



The eighteenth century continued the same work of 

 patient enquiry, completing the harmony of astronomy by 

 bringing the observed movements of the planets under 

 Newton's law of gravitation ; founding chemistry upon a 

 firm basis of careful experiment ; creating the sciences of 

 zoology and botany, by establishing true systems of classi- 

 fication ; discovering the hitherto almost unknown force of 

 electricity; and reading in the crust of the earth the history 

 of the past ages of our planet. 



And so when the nineteenth century opened, men found 

 themselves with an immense mass of known facts and 

 careful experiments, which had been accumulated during 

 the last two centuries, and which were very difficult to deal 

 with, because it had become almost impossible for any single 

 mind to grasp them all. The scientific men of our century 

 have therefore become divided into two great classes. On the 

 one hand men have devoted themselves to special sciences, 

 and even to special branches of a science, so that a man will 

 often spend his whole life in the study of one department of 

 chemistry or physics, or in investigating one little group of 



