Here Humboldt and Goethe became earnest friends. Goethe says: "During Humboldt's visit, my time has been usefully and agreeably spent; his presence has had the effect of arousing from its winter sleep my taste for natural science." Years afterward Goethe said to Eckermann: "Alexander von Humboldt has been with me for some hours this morning; what an extraordinary man he is! Though I have known him for so long, I am always struck with fresh amazement in his company. He may be said to be without a rival in extent of information and acquaintance with existing sciences. He possesses, too, a versatility of genius which I have never seen equalled. Whatever may be the subject broached, he seems quite at home in it, and showers upon us treasures in profusion from his stores of knowledge. He resembles a living fountain, whence flow many streams, yielding to all comers a quickening and refreshing draught. He will remain here a few days, and I already feel that I shall have lived through years in the time." That Humboldt valued this friendship is shown by the dedication to Goethe of the first part of his "Travels in America." The project of foreign travel was long delayed by sickness, war, and various disappointments. But, in life, obstacles are the common lot of mortals, and he alone is wise who breasts them cheerfully, patiently, and persistently. Humboldt said, "It is impossible not to feel the severity of this disappointment; but it is the part of a man to work, and not to yield to unavailing regrets." "Hard! well, and what of that? Didst fancy life one summer holiday, With lessons none to learn, and naught but play? Go, get thee to thy task. Conquer or die! It must be learned. Learn it then, patiently." At last, in 1799, when Humboldt was thirty, the long contemplated journey to South America was about to be realized. He had already published some astronomical treatises on the determination of latitudes, trigonometrical measures of the Alpine ranges, etc.; had given lectures in Paris, before the National Institute, on the nature of nitrous gas, and the possibility of a more exact analysis of the atmosphere; and had spent some time in Spain, with the well known botanist Bonpland, in collecting plants, and making observations in connection with meteorology, geology, and magnetism. While at Madrid, through Herr von Forell, a distinguished patron of science, Humboldt was received at court and obtained permission of the king to visit the Spanish colonies in America.