286 The Founders of Geology LECT. 



no limit can be set. He may be enabled to rebuild parts 

 of the temple of science, or to add new towers and pinnacles 

 to its superstructure. But even if he should never venture 

 into such ambitious undertakings, he will gain, in the 

 cultivation of geological pursuits, a solace and enjoyment 

 amid the cares of life, which will become to him a source 

 of the purest joy. 



In the second place, the history of our science presents 

 some conspicuous examples of the length of time that 

 may elapse before a fecund idea comes to germinate and 

 bear fruit. Consider for a moment how many years 

 passed before the stratigraphical conceptions of Fuchsel and 

 Giraud-Soulavie took more definite shape in the detailed 

 investigations of Cuvier, Brongniart and Smith, and how 

 many more years were needed before the Secondary and 

 Tertiary formations were definitely arranged and sub- 

 divided. Eemember too that even after the principles of 

 stratigraphy had been settled, a quarter of a century had 

 slipped away before they were successfully applied to the 

 Transition rocks. Mark the history of physiographical 

 geology, and note that though the principles of this branch 

 of science were firmly grasped by Desmarest and Hutton 

 in last century, their work was neglected and forgotten 

 until the whole subject has been revived and marvellously 

 extended in our own day. Again let me recall how 

 slowly the key that unlocks the innermost mysteries of 

 rock-structure was made use of. Five-and-twenty years 

 elapsed after William Nicol had shown how stony sub- 

 stances could be investigated by means of the microscope, 

 before Mr. Sorby called the attention of geologists to the 

 enormous value of the method thus put into their hands. 



