52 ALEXANDER VON HTJMBOLDT. 



getting married to a Fraulein von Dacherb'den, and in his 

 present humour declines all public employment, which, with 

 his talents, is much to be regretted. Alexander, on the con- 

 trary, is most anxious to work, but he has not the physical 

 power.' 



Even in 1795 Humboldt is obliged thus to allude to his 

 health in a letter to Willdenow : ' You have a right to be 

 angry with me for writing so seldom. Yet if you knew the 

 circumstances in which I am placed that I am constantly 

 travelling about, and that I was laid up for three months last 

 winter with a serious illness, which obliges me to devote the 

 little leisure I now have to study you would at least accept 

 my excuses, even if you could not justify me.' 



At a still later period even, Kunth expresses some anxiety 

 about his health in a letter to Von Moll of September 17, 

 1799: 'If his health,' he writes, 'does not succumb to the 

 climate and the hardships of travel, how much valuable infor- 

 mation may not be expected in various departments of physical 

 science from the observations of one who, possessed of such 

 extensive knowledge, and burning with zeal for the investiga- 

 tion of nature, is intending to spend years together in the 

 midst of scenes of such sublimity.' 



Fortunately, however, delicate constitutions often suffer less 

 from the change to a foreign climate and the hardships of 

 travel than those natures which appear to be more robust. 

 Thus Irwin survived all the privations of the desert surrounding- 

 Thebes, while Ledyard, though much more vigorous, fell a 

 victim to the climate before leaving Cairo ; and Seetzen, consti- 

 tutionally delicate, successfully combated the dangers of tra- 

 vel in Syria, Egypt, and Arabia, while his stronger and more 

 hardy companion, Jacobsen, was compelled, on account of the 

 climate, to leave the expedition at Smyrna. Humboldt de- 

 scribes himself as being equally in his element in the region 

 of the tropics as within the circle of the poles. 



For some years prior to their departure for the University, 

 the brothers resided more frequently at Berlin than at Tegel ; 

 for only in the capital could they procure the assistance of 

 tutors capable of undertaking the various branches of their 

 education and enjoy the advantages necessary for their prepa- 



