Considering myself highly honored by this kind invitation, I felt it necessary to endeavour at once to gratify a desire expressed in such flattering terms. But, after mature reflection, I resolved to confine myself to the publication of official documents; and it was again necessary to choose from these on account of my limits. I have thus been prevented from publishing letters of the honorable president of the Court of accounts; the director of the King's library; the secretary of the society for the encouragement of silk culture; the president of the Royal academy of Rouen; the perpetual secretaries of the Royal and central agricultural society; of the academy of science, of the academy of moral and political science. All these letters were accompanied by documents and books which have been faithfully transmitted to their respective destinations in the United States. It can be easily understood, that, obliged even to reduce the number of documents which each testified to the positive results of the system of exchanges, I have entirely omitted those which merely contain promises. In the present state of things, I can only with propriety present the public with accomplished facts. Why should I add any reflection to these authentic documents which I publish? It does not become me to tell the care and anxiety which the already acquired results have cost me. As for the kindness and liberality of which so many proofs have been given me both in France and America, it is visible enough through this publication. If, on this occasion, I express my unbounded gratitude, I cannot nevertheless forget that these favors have been granted less to my exertions than in consequence of the hopes thereby created, and the ends foreseen. I hope that this pamphlet will not be without fruit. From what has been done, we can judge of what may be done, and inspired by the confidence imparted by the success of the three past years, I confidently trust that these facts will give the system of exchange a new impulse. For this reason, I have determined to conclude the publication by the instructions prepared by the administrative professors of the Museum of natural history. Our American Brethren will be kind enough to follow the advice of these literati in prosecuting their researches, and sending their fruits. I beg leave to recommend them to the particular attention of those societies and gentlemen in the new world who make natural history a special study. The French and English languages being so familiar to the two nations, I thought it better to keep the following Documents in the language they were writt, fearing they might lose their originalety by being translated. Paris, may 1846. A. VATTEMARE. PRESENT STATE OF THE SYSTEM OF INTERNATIONAL LITERARY EXCHANGES BETWEEN FRANCE AND NORTH AMERICA. EXTRACT _from the_ JOURNAL DE L'INSTRUCTION PUBLIQUE (March 4. 1846.) (_Published under the auspices of the Department of public instruction_).