SIR,--I received, in due time, your favor of April 10th, enclosing a scheme and subscription for the establishment of a museum of natural history, at Williamsburgh, by private contributions. Nobody can desire more ardently than myself, to concur in whatever may promote useful science, and I view no science with more partiality than natural history. But I have ever believed that in this, as in most other cases, abortive attempts retard rather than promote this object. To be really useful we must keep pace with the state of society, and not dishearten it by attempts at what its population, means, or occupations will fail in attempting. In the particular enterprises for museums, we have seen the populous and wealthy cities of Boston and New York unable to found or maintain such an institution. The feeble condition of that in each of these places sufficiently proves this. In Philadelphia alone, has this attempt succeeded to a good degree? It has been owing there to a measure of zeal and perseverance in an individual rarely equalled; to a population, crowded, wealthy, and more than usually addicted to the pursuit of knowledge. And, with all this, the institution does not maintain itself. The proprietor has been obliged to return to the practice of his original profession to help it on. I know, indeed, that there are many individuals in Williamsburg, and its vicinity, who have already attained a high degree of science, and many zealously pursuing it. But after viewing all circumstances there as favorably as the most sanguine of us could wish, I cannot find in them a rational ground for expecting success in an undertaking to which the other positions have been found unequal. I sincerely wish I may be mistaken, and that the success which your zeal I am sure will merit, may be equal to your wishes, as well as ours. But, for the present, I would rather reserve myself till its prospects can be more favorably estimated; because the aid we would be disposed to give to a promising enterprise, would be very different to one we might offer to a desperate one. Although less sanguine on this particular subject, I do entire justice to the zeal for the promotion of science, which has excited your effort, and shall see it with uncommon pleasure surmounting the present difficulties, or engaged in other pursuits which may reward it with better success. Be assured that no one is more sincere in wishing it, and accept my salutations and assurances of great respect and consideration. TO MR. CLINTON. WASHINGTON, May 24, 1807.