OFFICIAL EMPLOYMENT. 133 



slightest relation to the subject. As a result, I am now as 

 firmly convinced of the fact of oxygen being the principle of 

 vital power (notwithstanding the mysterious galvanic fluid, 

 which is certainly neither magnetic nor electric), as you were 

 when you first told me about it in Grreen Park. Since then, 

 nothing that you have written has appeared to me of greater 

 value than the admirable section on vegetation in your 

 " First Principles of Antiphlogistic Chemistry," for which 

 I hope soon to have an opportunity of publicly expressing 

 my deep obligations. . . . All my leisure now is devoted to j 

 chemistry, especially to the chemistry of the physiology of 

 plants, for the study of which I am provided with efficient 

 apparatus. I intend some day to devote more time to this 

 subject. I have instituted a series of experiments on the ger- 

 mination and growth of plants in various substances supposed 

 to be unfavourable to vegetable life.' An account of these 

 experiments appeared in various periodicals. 



In April Humboldt went to Schonebeck, to plan the con- 

 struction of some salt works, and shortly after his return to 

 Berlin, upon the completion of the publication of the ' Flora 

 Fribergensis,' started in May for Franconia. On his way he 

 paid a visit to his brother and his family at Erfurt, whence 

 he wrote to his friend Freiesleben on May 26, 1793 : 



''I leave to-night for Bayreuth. I am now officially en- 

 gaged in practical mining, of which I was so ignorant only two 

 years ago as to be learning from you what a lode [Spatgang] 



was I possess a certain amount of vanity, and am 



willing to confess it ; but I know the power of my own will, 

 and I feel that whatever I set myself to do, I shall do well.' 

 Then a feeling of diffidence passes over him. ' But little,' he 

 remarks, ' is expected from a Counsellor or Overseer of Mines, 

 one is too much accustomed to incompetency ; but a Superin- 

 tendent ! However, there is no help for it.' 



In order to follow him intelligently in the prosecution of 

 this commission in Franconia, it will be well to take a glance 

 at the political condition of the principalities, and to pass in 

 review the men who were associated with him in his official 

 labours. 



Upon the annexation by Prussia of the margraviate of 



