X OBITTJABY 293 



composed, and that changes in external conditions 

 favour some and hinder others. 



After a short stay in Cambridge, Darwin resided 

 in London for the first five years which followed 

 his return to England ; and for three years, he held 

 the post of Secretary to the Geological Society, 

 though he shared to the full his friend Lyell's 

 objection to entanglement in such engagements. 

 In fact, he used to say in later life, more than half 

 in earnest, that he gave up hoping for work from 

 men who accepted official duties and, especially, 

 Government appointments. Happily for him, he 

 was exempted from the necessity of making any 

 sacrifice of this kind, but an even heavier burden 

 was laid upon him. During the earlier half of his 

 voyage Darwin retained the vigorous health of his 

 boyhood, and indeed proved himself to be excep- 

 tionally capable of enduring fatigue and privation. 

 An anomalous but severe disorder, which laid him 

 up for several weeks at Valparaiso in 1834, how- 

 ever, seems to have left its mark on his constitution ; 

 and, in the later years of his London life, attacks 

 of illness, usually accompanied by severe vomiting 

 and great prostration of strength, became frequent. 

 As he grew older, a considerable part of every day, 

 even at his best times, was spent in misery ; while, 

 not unfrequently, months of suffering rendered work 

 of any kind impossible. Even Darwin's remarkable 

 tenacity of purpose and methodical utilisation of 



