D'ALEMBERT. 395 



and that he then took no keep of time is undeniable. 

 It does not require the same depth of understanding 

 to experience the effects of such pursuits in producing 

 complete abstraction; every geometrician is aware of 

 them in his own case. The sun goes down unperceived, 

 and the night wanes afterwards till he again rises upon 

 our labours. 



They who have experienced an incurable wound in 

 some prodigious mental affliction, have confessed, that 

 nothing but mathematical researches could withdraw 

 their attention from their situation. Instances we know 

 of a habit of drinking being cured by the like means ; an 

 inveterate taste for play has within my own observation 

 been found to give way before the revival of an early love 

 of analytical studies. This is possibly a cause of the 

 other tendency, which has been mentioned, the calming 

 of the mind. We have seen in the life of Simson, how 

 he would fly from the conflicts of metaphysical and 

 theological science, to that of necessary truth, and how 

 in those calm retreats he ever " found himself refreshed 

 with rest."""" Greater tranquillity is possessed by none 

 than by geometricians. Even under severe privations 

 this is observed. The greatest of them all, certainly the 

 greatest after Newton, was an example. Euler lost his 

 sight after a long expectation of this calamity, which he 

 bore with perfectly equal mind; both in the dreadful 

 prospect and the actual bereavement, his temper con- 

 tinued as cheerful as before, and his mind, fertile in 

 resources of every kind, supplied the want of sight by 

 ingenious mechanical devices, and by a memory more 



* Vol. i., p. 477. 



