148 SKETCH OF THE LIFE AND ACHIEVEMENTS 



early departure of Willielm ; and in a subsequent 

 letter to Arago, April 10th, he relates the sad 

 loss of his brother in these words : " Je suis 

 dans le plus profond abattemeiit. Dans les 

 plus grandes douleurs on pense a ceux qui 

 nous sont les plus chers ; je me sens un pen 

 soulage en vous ecrivant. . . . Je reste bien 

 isoleV' 



Alexander von Humboldt honoured the 

 memory of his departed brother, above all, by 

 the regular publication of his literary works. 



Soon after this sad event, Humboldt was 

 again exclusively engaged in his scientific in- 

 vestigations ; and contributed continually to the 

 general acquisitions of science. The publication 

 of the results of his expedition to Central Asia 

 demanded still his principal attention : a variety 

 of other scientific works already commenced, 

 and especially his " Critical Examinations with 

 reference to the Historical Development of the 

 Geography of the New World, and the Progress 

 of Nautical Astronomy in the 15th and 16th 

 Century." In four regular divisions, Humboldt 

 treated of, 1. "the Causes which originated and 

 accomplished the discovery of the New World ; 

 2. some facts more especially connected with 

 Christopher Columbus and Amerigo Vespucci, 

 and various dates of geographical discoveries ; 



