At college, as ever after in life, he found one devoted friend, who became his inseparable companion. At Frankfort, it was Wegener, a young theologian, with a warm heart, and great zeal for knowledge. Nor did this friendship cease when he went to Göttingen some months later, for better opportunities in the study of science. He wrote to Wegener: "If God only spare us, nothing can break the bond between two friends who are to each other more than brothers.... My fervent love and sincere friendship for you are as imperishable as the soul which gives them birth.... How happy, how inexpressibly happy should I be, if I had a friend like you by my side!... I doubt not that among eight hundred men there must be some with whom I could form a friendship, but how long is it often before we find each other out! Were not you and I acquainted for three months before we discovered how completely we were made one for the other? To be without a friend, what an existence! And where can I hope to find a friend whom I could place by your side in my affections!" These words seem like those of a lover, or an affectionate woman, but they come from a mind that now, as in after years, towered like a giant oak in the trees of a forest. Beautiful union of brain and heart! Such only makes an ideal character. Humboldt had already met Willdenow, and begun to love botany. Again he writes to Wegener: "I have just come in from a solitary walk in the Thiergarten,"--he was for a short time in Berlin,--"where I have been seeking for mosses, lichens, and fungi, which are just now in perfection. How sad to wander about alone! And yet there is something attractive in this solitude, when occupied with nature.... I am collecting materials for a work on the various properties of plants, medicinal properties excepted; it is a work requiring such great research, and such a profound knowledge of botany, as to be far beyond my unassisted powers, and I am therefore endeavoring to enlist the coöperation of several of my friends.... Pray do not imagine that I am going to appear as an author forthwith; I do not intend that shall happen for the next ten years, and by that time I trust I shall have discovered something startlingly new and important." Göttingen was now at the height of its glory. Humboldt attended courses of lectures on archæology, on trade and commerce, on light, heat, and electricity, on agriculture, and on ancient tragic poets, under Heyne, of whom he said, "Heyne is undoubtedly the man to whom this century is the most deeply indebted; to him we owe the spread of religious enlightenment, by means of the education and training he has instituted for young village school-masters; to him is due the introduction of a more liberal tone of thought, the establishment of a literary archæology, and the first association of the principles of æsthetics with the study of philology."