xxv.] ACCORDANCE OF THEORIES. 573 



be referred to casual errors of observation or to some new 

 phenomenon. But nothing is more requisite for the pro- 

 gress of science than the careful recording and investigation 

 of such discrepancies. In no part of physical science can 

 we be free from exceptions and outstanding facts, of which 

 our present knowledge can give no account. It is among 

 such anomalies that we must look for the clues to new 

 realms of facts worthy of discovery. They are like the 

 floating waifs which led Columbus to suspect the existence 

 of the new world. 



