The Appeal of Baron Humboldt.

--The great naturalist and philosopher, Humboldt, has at last been compelled to put forth an appeal to the world for mercy; he implores his assiduous friends to spare him from their overwhelming honors and attention.

The following card has appeared in the Berlin Journal:

Berlin, March 15, 1859.

Suffering beneath the pressure of a still increasing correspondence, amounting to between sixteen hundred and two thousand communications per annum, and embracing letters, printed pamphlets on matters with which I am wholly unacquainted, manuscripts concerning which my opinion is desired, projects for emigration and colonization, the transmission of models, machines, and objects of natural history, inquiries about aerostatics, requests of contributions to collections of autographs, offers to take charge of my domestic concerns, to amuse me, &c., I must again publicly urge all persons having my welfare at heart to exert their influence in my behalf, that individu- als in both continents may no longer trouble themselves with my person and make of my house an intelligence office; and that I be allowed, in the declining state of my physical and mental powers, to enjoy some rest and leisure to attend to my duties.

May this cry for relief, which I utter with much reluctance and after long delay not meet an unfriendly interpretation!

Alexander von Humboldt.