Von Humboldt’s Expedition to Spanish America. The two following letters from this indefatigable philoſopher to one of his friends in Germany, have been publiſhed in one of the foreign journals:— Corunna, June 3, 1799. I wrote you from Marſeilles, that I had been diſappointed in my hopes of undertaking a voyage round the world with Captain Baudin (to which I had been invited by the French Government) juſt at the moment when I was going down to the port to embark. After this I propoſed to go out to Bonaparte with the ſecond expedition from Toulon, and my friends were anxiouſly expecting me; but this expedition was rendered impoſſible by the battle of Aboukir. Firm to my purpoſe, I then wiſhed to go by a Swediſh frigate, expected at Marſeilles, to Algiers, in order that I might undertake, with the caravan of Mecca, that dangerous journey through the deſart of Selima to Cairo. The frigate, however, did not arrive; and, after waiting two months to no purpoſe in Provence, as war had broken out between France and Algiers, I proceeded to Spain. I had procured recommendations to the king, and received from him what no foreigner ever obtained—letters of recommendation to all the viceroys, and permiſſion to traverſe all the Spaniſh ſettlements with my inſtruments. You muſt acknowledge that I have been exceedingly fortunate. I have been provided with every thing neceſſary, and in a few hours ſhall ſail, in the Spaniſh frigate Pizarro, for the Havannah; from which I intend to proceed to Peru, Mexiko, and Chili. I ſhall be abſent for ſeveral years, but I flatter myſelf with the hopes of accompliſhing ſomething of importance. Bonpland, a young French botaniſt; accompanies me. I ſhall write you from the Havannah. Alex. Von Humboldt. Orotava in the Iſland of Teneriffe, June 24, 1799. We left Corunna on the 5th, and arrived, without any accident, at Lancerotta on the 16th, and St. Croix, in Teneriffe, on the 17th. We were in ſight of four Engliſh frigates, which we eſcaped, but we cannot tell how. I have examined the peak with great attention; I was almoſt in the crater at the height of 11,500 feet. This excurſion was attended with more fatigue than danger. We found the heat of the crater on the ground 70° Reaum. and the air at 2°. The pumice-ſtone, which has occaſioned ſo much diſpute, is obſidian-ſtone fuſed and decompoſed. It is here as clear as the day. I am ſo tired that I muſt conclude my letter. We are juſt going to ſet out for Caraccas and the Havannah. Alex. Von Humboldt.