MENTAL QUALITIES. IO7 



a little use for my particular line of work. Lastly, I 

 have had ample leisure from not having to earn my 

 own bread. Even ill-health, though it has annihilated 

 several years of my life, has saved me from the dis- 

 tractions of society and amusement. 



Therefore my success as a man of science, whatever 

 this may have amounted to, has been determined, as 

 far as I can judge, by complex and diversified mental 

 qualities and conditions. Of these, the most important 

 have been the love of science unbounded patience 

 in long reflecting over any subject industry in observ- 

 ing and collecting facts and a fair share of invention 

 as well as of common sense. With such moderate 

 abilities as I possess, it is truly surprising that I should 

 have influenced to a considerable extent the belief of 

 scientific men on some important points. 



