From the London Times.

BARON VON HUMBOLDT ON SLAVERY IN THE UNITED STATES AND IN CUBA.

Baron von Humboldt has caused the following article to be inserted in the Spnerche Zeitung.

“Under the title of Essai Politique sur l'Isle de Cuba, published in paris in 1826, I collected together all that the large edition of my Voyage aux Regions Equinaxiales du Nouceau Continnent contained upon the state of agriculture and slavery in the Antilles.

There appeared at the same time an English and a Spanish Translation of this work the latter entitled Essayo Politico sobre la Isla de Cuba, neither of which omitted any of the frank and open remarka which my feelings humanity had inspired.

But there appeara just now, strangely enough, translated from the Spanish translation, and not from the French original, and published by Derby and Jackson, in New York, an octavo volume of 400 pages under the title of The Island of Cuba, by Alexander Humboldt; with notes and a preliminary essay by J.S. Thrasher.

The translator, who has lived a long time on that beautiful island, has enriched my work by more recent data on the subject of the numerical standing of the population, of the cultivation of the soil, and the state of trade, and generally sponking, exhibited a charitable moderation in his discussion of conflicting opinions.

I owe it, however, to a moral feeling, that is now as lively in me as it was in 1826, publicly to complain that in a work which bears my name the entire serenth chapter of the Spanish translation, with which my essai politique ended, has been arbitrarily omitted.

To this very portion of my work I attach greater importaner than to any astronomical observations, experiments of magnetic intensity, or statistical statements.

“I have examined with frankness (I here repeat the words I used thirty years ago) whatever concorns the organization of human society in the colonies the unequal distribution of the rights and enjoyments of life, and the impending dangers which the wisdom of legislators and the moderation of freemen can avert, whatever may be the form of government.

“It is the duty of the traveler who has been an eye witness of all that tortures and degrades human nature to cause the complaints of the unfortunate to reach those whose duty it is to relieve them. I have repeated in this treatise the fact that the ancient legislation of Spain on the subject of slavery is loss inhuman and atrocious than that of the slave Staten on the American Continent.

North or South of the Eqantor.

“A steady advocate as I am for the most unfettered expression of opinion in speech or in writing I should never have thought of complaining if I had been attacked on account of my statements: but I do think I am entitled to demand that in the free States of the continent of America people should be allowed to read what has been permitted to circulate from the first year of its appearance in a Spanish translation.

“ALEXANDER VON HUMBOLDT.”

“Berlin, July, 1855.”