94 ALEXANDER VON HUMBOLDT. 



words were necessary ! With renewed expressions of heart- 

 felt thanks and friendly esteem, I remain yours with the high- 

 est respect, 



' A. YON HUMBOLDT.' 



Humboldt remained a guest with Forster till the end of July. 

 It was at this time that he made the acquaintance of Sommering, 

 with whom he at once entered into a lively correspondence ; his 

 celebrated work, c Experiments upon the Excitability of the 

 Muscles and Nerves,' is dedicated ' with grateful respect and 

 affection to the distinguished anatomist Sommering.' While 

 staying with Forster he wrote the following letter to Werner at 

 Freiberg, a noted professor of the science of mining and the 

 most distinguished geologist of the day : 



' Mayence : July 25, 1790. 



' Sir, I venture to send you a small pamphlet in which I 

 have propounded certain views upon the columnar basalts of 

 the Rhine. Although I can scarcely flatter myself that this 

 youthful production will gain your approval, I gladly avail 

 myself of this opportunity to express to you my profound 

 respect for your successful efforts in remodelling the science of 

 mineralogy. Unfortunately, I am not one of those who enjoy 

 the advantage of your personal instruction, and who can there- 

 fore observe under your own guidance the position of minerals 

 and fossils in their natural bed. Various circumstances have 

 prevented me hitherto from visiting the admirable institution 

 at Freiberg ; but perhaps I may yet be fortunate enough at 

 some future time to enroll myself as one of your pupils. I 

 have in the meanwhile, as far as my powers will allow me, 

 endeavoured so to familiarise myself with your system as to 

 adopt your ideas and your expressions as my own. How far I 

 have succeeded I must respectfully leave it to you to decide. 



6 In my journey to England, whence I have just returned, I 

 traversed for a second time the mountains of the Rhine. I found 

 nothing to necessitate the supposition of previous volcanic 

 agency, but on the contrary abundant evidence to prove the 

 aqueous formation of basalt. Your theory that a stratum of 



oath of citizenship before March 30 ; -while he himself had already set out on 

 his fatal journey to Paris on March 25. 



