ALEXANDER VON HUMBOLDT. 121 



and scientific work, with two friends, Freiesleben, 

 and Lieutenant Reinhard von Haften, of West- 

 phalia, he journeyed to Venice, going through the 

 Tyrol and the Alps into Switzerland. They visited 

 the mountains around Schaffhausen, Zurich, and 

 Berne, and such notable men of science as De Luc, 

 Pictet, and Saussure. As Freiesleben said, "No 

 subject having any reference to the physical con- 

 stitution of the earth, the atmosphere, or any 

 point of natural history, was allowed to escape his 

 attention." 



An especial bond united Humboldt and the 

 highly educated Von Haften, since between the 

 latter's sister Minette and the young scientist there 

 existed a devoted affection. This was cherished 

 for ten years, but Humboldt's life of travel and 

 exposure prevented a union which both ardently 

 desired. He sacrificed his affections to science, 

 and the loneliness of his later years proved the 

 unwisdom of his choice. 



On his return home, Humboldt set himself ear- 

 nestly to the writing of two books : one 011 geol- 

 ogy, the disposition of strata in mountain masses ; 

 the other on the " Excitability of the Nerves and 

 Muscles,' 7 describing over four thousand experi- 

 ments. His devotion to science was shown by 

 the painful experiments upon his own body, which 

 brought permanent harm to his nervous system. 



He wrote to a friend : " I applied two blisters to 

 my back, each of the size of a crown-piece, and 

 covering respectively the trapezius and deltoid 



