M. De Buch.--The following is a translation of an affecting letter from the veteran Baron Alexander Humboldt to Sir Roderick Murchison, the original of which has been kindly communicated by Sir. Roderick to us (Athenoeum). It conveys intelligence which will be beard with great regret in the scientific world of England:-- "Berlin, March 4. 1853. "That I should be destined--I. an old man of 83--to announce to you, dear Roderick the saddest news that I could have to convey--to you for whom M. De Buch professed a friendship so tender--and to the many admirers of his genius. his vast labours, and his noble character! Leopold De Buch was taken from us this morning by typhoid fever--so violent in its attack that two days only of danger warned us. He was at my house no lately as the 26th ult., despite the snow and the distance between us--talking geology with the most lively interest. That evening he went into society, and on Sunday and Monday (the 27th and 28th) he complained of a feverish attack, which he believed to be caused by a large chilblain swelling from which he had suffered for years. The inflammation required the application of leeches--but the pain and the fever increased. He was speechless for 38 hours... He died surrounded by his friends, most of whom knew nothing of his danger till Wednesday evening, the 2nd of March. He and I were united by a friendship of 63 years--a friendship which never knew interruption. I found him in 1791, in Werner's house in Freiberg, when I entered the School of Mines. We were together in Italy, in Switzerland, in France. four months in Saltzburg. M. De Buch was not only one of the great illustrations of his age--he was a man of noble soul. His mind left a track of light wherever it passed Always in contact with Nature herself--he could boast of having extended the limits of geological science. I grieve for him profoundly--without him I feel desolate. I consulted him as master; and his affection (like that of Gay Lussac and that of Arago. who were also his friends) sustained me in my labours. He was four years my junior--and nothing forewarned me of this misfortune. It is not at the distance of a few hours only from such a loss that I can say more respecting it. Pity me--and accept the homage of my profound respect and affectionate devotion. "Al. Humboldt. "And my poor countryman Overweg, in Africa! What a blessing to learn one day by means of the astronomer Vogel the magnetic condition of the interior of a vast continent!"