DEAR SIR,--The biography of Mr. Vander Kemp would require a volume which I could not write if a million were offered me as a reward for the work. After a learned and scientific education he entered the army in Holland, and served as captain, with reputation; but loving books more than arms he resigned his commission and became a preacher. My acquaintance with him commenced at Leyden in 1790. He was then minister of the Menonist congregation, the richest in Europe; in that city, where he was celebrated as the most elegant writer in the Dutch language, he was the intimate friend of Luzac and De Gysecaar. In 1788, when the King of Prussia threatened Holland with invasion, his party insisted on his taking a command in the army of defence, and he was appointed to the command of the most exposed and most important post in the seven provinces. He was soon surrounded by the Prussian forces; but he defended his fortress with a prudence, fortitude, patience, and perseverance, which were admired by all Europe; till, abandoned by his nation, destitute of provisions and ammunition, still refusing to surrender, he was offered the most honorable capitulation. He accepted it; was offered very advantageous proposals; but despairing of the liberties of his country, he retired to Antwerp, determined to emigrate to New York; wrote to me in London, requesting letters of introduction. I sent him letters to Governor Clinton, and several others of our little great men. His history in this country is equally curious and affecting. He left property in Holland, which the revolutions there have annihilated; and I fear is now pinched with poverty. His head is deeply learned and his heart is pure. I scarcely know a more amiable character. * * * * * He has written to me occasionally, and I have answered his letters in great haste. You may well suppose that such a man has not always been able to understand our American politics. Nor have I. Had he been as great a master of our language as he was of his own, he would have been at this day one of the most conspicuous characters in the United States. So much for Vander Kemp; now for your letter of August 1st. Your poet, the Ionian I suppose, ought to have told us whether Jove, in the distribution of good and evil from his two urns, observes any rule of equity or not; whether he thunders out flames of eternal fire on the many, and power, and glory, and felicity on the few, without any consideration of justice? Let us state a few questions _sub rosâ_. 1. Would you accept a life, if offered you, of equal pleasure and pain? For example. One million of moments of pleasure, and one million of moments of pain! (1,000,000 moments of pleasure = 1,000,000 moments of pain.) Suppose the pleasure as exquisite as any in life, and the pain as exquisite as any; for example, stone-gravel, gout, headache, earache, toothache, cholic, &c. I would not. I would rather be blotted out.