184 SKETCH OP THE LIFE AND ACHIEVEMENTS 



gical districts, which will be of importance in 

 furtherance of my work on the different strata." 



New political differences called Humboldt 

 again, in 1796, to the field of diplomacy. He 

 had hastened from Bayreuth to Berlin, in order 

 to remain for a few months near his mother, 

 who had suffered for a considerable time from a 

 lingering disease, when this unexpected sum- 

 mons arrived. The French army under the 

 command of General Moreau had suddenly in- 

 vaded the duchy of Wiirtemberg, and had caused 

 the flight of the Duke. The King of Prussia 

 feared that the principality of Hohenlohe might 

 be subject to the pillage of the advancing army 

 under Moreau and Jourdan, but hoped, in 

 consequence of the existing amicable relations 

 of Prussia and France, obtained by the treaty 

 of peace concluded at Basle, April 5th, 1795, 

 by the Prussian minister von Hardenberg, to 

 dispose the French general favourably concern- 

 ing this principality. 



Humboldt proceeded, in company of a Cap- 

 tain Pirch and a single trumpeter, to the head- 

 quarters of the French army. On his road he 

 observed the noted balloon of Conde, ivhich had 

 been kept filled for months, and in which General 

 St. Oyr watched the movements of the enemy 

 at the battle of Cannstadt. 



