350 THE POPULAR SCIENCE MONTHLY 



he never lost a friend) he was almost as famous for his social as for his 

 scientific victories. Yet he never married. 



It was with real sorrow that he obeyed the command of his king and 

 left his dearly loved Paris to pass the remainder of his life in Potsdam. 

 He was in the fifty-ninth year of his age, in perfect health and deeply 

 interested in every department of learning as well as in those special 

 fields to which he had given personal attention. A home was provided 

 for him at Potsdam, a liberal salary paid him regularly, so that, barring 

 the demands which the king made upon him for diplomatic services 

 (and these were not infrequent), as a companion of his official visits, or 

 as a visitor at the palace, he was free to pursue his studies. The 

 German public, proud of his renown, rejoiced in his return to his 

 native land and read with increasing interest and enthusiasm whatever 

 came from his pen. 



His lectures at Berlin in the winter of 1827 and 1828, which formed 

 the basis of " Cosmos," were heard with astonishment and delight. 



A man like Humboldt, so widely known and so thoroughly trained as 

 an explorer and observer, could not long be permitted to remain quiet in 

 any one place. At the request of the Czar of Eussia, under his protec- 

 tion and at his expense, with Ehrenberg, the microscopist, Gustav Eose, 

 the chemist, and Menscherlisch, an engineer, he made a rapid but intel- 

 ligent survey of Asiatic Eussia, giving particular attention to the Ural 

 and Aral Mountain chains. It was on this journey that diamonds were 

 discovered in the Ural Mountains and secured to the government for 

 its control and profit. Ehrenberg and Eose published separate accounts 

 of this journey and Humboldt's " Central Asia " is an enlargement and 

 revision of his first report, which appeared simply as a fragment, on the 

 geology and mineralogy of the country. 



While in Paris he had experimented with Gay-Lussac on the nature 

 and qualities- of gas, and with him as a companion had visited Eome, 

 where his brother William was the Prussian minister, in order to study 

 magnetism. It would take a good-sized volume to give an account of 

 the various services he rendered the king, and of the journeys he made 

 as a diplomat, nearly always with success, and in the interest of science. 

 He was in the seventy-sixth year of his age when he made public his inten- 

 tion of writing that great work of his life known as " Cosmos." Previous 

 treatises he looked upon as preliminary sketches compared with the work 

 he would now compose and in which he would try to give an accurate 

 and sufficiently full account of all existing scientific knowledge. In this 

 work, while presenting general rather than detailed conclusions or 

 statements, he would show that nature, in spite of her seeming com- 

 plexity, is yet a unit and governed by a definite and well-ordered plan. 

 A master of the materials furnished by the most eminent scientists of 

 the day, without claiming for himself to be an authority in any single 

 department of science, he believed himself better fitted by reason of 



