The Moniteur of the 11th contains a long letter to the Editor from M. De Humboldt, in which he brings a charge of plagiarism against Mr. Arrowsmith, a well-known English Geographer.

After some prefatory observations, M. De H. proceeds as follows:—

“I was engaged during four years in the construction of a map of Mexico, which was published at Paris, in September, 1809, in two large sheets , in my ‘Geographical and Physical Atlas of the Kingdom of New Spain.’ I had first drawn it up in Mexico, in 1803, and it was engraved at Paris by M. M.

Aubert and Barriere: it was entitled, ‘General Map of the Kingdom of New Spain, drawn up from astronomical observations, and the whole of the materials which existed in Mexico, at the commencement of the year 1804, by Alexander De Humboldt.’ The astronomical observations, the geodesic surveys, and the barometrical admeasurements of heights which I made in the course of my travels in the equinoctial regions of the New Continent, from 1799 to 1803, are to be found in the second volume of my ‘Collection of Astronomical Observations,’ published conjointly with M. Oltmanns.

The numerous and unpublished materials which assisted in the construction of the 20 maps contained in the Mexican atlas, are indicated and discussed in an analysis prefixed to my Political Essay on the kingdom of New Spain.

“All these long and painful labours, however imperfect they appear to me, Mr. Arrowsmith has entirely appropriated to himself; he faithfully copied my general map of Mexico, and published it in London, before the appearance of the English translation of my Political Essay; and he substituted his own name instead of mine, under the title of “New Map of Mexico, compiled from original documents, by Arrowsmith.”

The positions of the towns, of the villages and mines, the boundaries of the intendances, the ranges of mountains, the indications of the heights in toises, the notes on the migrations of the Azteques, and on the history of navigation, the small arrows annexed to a number of rivers, every thing, in short, is to be found in the copy of Mr. Arrowsmith. I was obliged to employ several new signs; for instance, two hammers placed crosswise to denote the chief station of a provincial council of the mines; and Mr. Arrowsmith, in adopting my signs, has also adopted their explanation; he has copied without translation, and without changing a single word; on his English map he has engraved my explanations in French, always leaving out the sign pointing to the places where I made astronomical observations.

If my name is looked for in the copy of the great map, it is only to be found in one of the three squares which contain the same number of sketches borrowed from my Mexican Atlas.

These small squares present hydrographic plans of the ports of Vera Cruz and Acapulco, and the chart of the valley of Mexico.

To the words “Valley of Mexico,”

Mr.

Arrowsmith has thought fit to annex the following words, “from M. Humboldt’s Map.”

But the only thing which Mr.

Arrowsmith choses to ascribe to me is not my own; it was a plan drawn up by D. Louis Martin, in 1804.

After a variety of other observations, M. de Humbolt adds, “This silence with regard to the sources of their information is become too common with geographers, particularly with those who do not accompany their maps with analytical memoirs on the subject of their construction, though a very different example has been given by the most distinguished of that class of literary men, such as d’Anville, Dalrymple, Fleurieu , and Rennell.”

M. d. H. concludes with expressing his hope, that the reclamations of a traveller will meet with some attention, when he proves that mere copies of his labours are disseminated under the name of another person.

The letter itself is written with every appearance of candour, and deserves the attention of those whom it concerns.