AN AUTOBIOGRAPHICAL SKETCH. 2G9 



by the fatigue of the work, and by vexation about all 

 kinds of futile steps which I had taken. My colleagues, 

 as well as the public at large, estimate a scientific or 

 artistic work according to the utility, the instruction, or 

 the pleasure which it has afforded. An author is usually 

 disposed to base his estimate on the labour it has 

 cost him, and it is but seldom that both kinds of 

 judgment agree. It can, on the other hand, be seen 

 from incidental expressions of some of the most cele- 

 brated men, especially of artists, that they lay but small 

 weight on productions which seem to us inimitable, 

 compared with others which have been difficult, and 

 yet which appear to readers and observers as much less 

 successful. I need only mention Groethe, who once 

 stated to Eckermann that he did not estimate his 

 poetical works so highly as what he had done in the 

 theory of colours. 



The same may have happened to me, though in a 

 more modest degree, if I may accept your assurances 

 and those of the authors of the addresses which have 

 reached me. Permit me, therefore, to give you a short 

 account of the manner in which I have been led to 

 the special direction of my work. 



In my first seven years I was a delicate boy, for 

 long confined to my room, and often even to bed ; but, 

 nevertheless, I had a strong inclination towards occupa- 

 tion and mental activity. My parents busied them- 

 selves a good deal with me ; picture books and games, 



