DEFENCE OF POLYGAMY.— A lady in Utah., a wife of one of the Mormon leaders, writes to her sister a letter, published in the newspapers, defending polygamy by the example of Abraham, Isaac and Jacob, and the holy men mentioned in the Bible.— The argument is as ingenious as many others drawn from the same source, and would be conclusive enough to satisfy the conscience of any Turk, whose harem contained not less than two hundred wives. The letter is a curiosity, as exhibiting the social relations of the polygamist. The lady says her husband has seven other wives, which is a moderate number for a leader of the faith, as Rig-don, the high priest of Mormonism, we believe, he thirty six The children of these eight wives num-ber twenty-five. The husband she says is a good and virtuous husband,' and all these mothers and children are endeared to her by kindred ties—by mutual affection—by acquaintance and association and the mothers in particular by mutual and long continued exercises of toil, patience, long suffering and sisterly kindness. The husband, of whose affections she is entitled to just one eighth, is a practical teacher of morals and religion, a promoter of general education; and at present occupies an honorable seat in the Legis-lative Council of the Territory. She concludes her remarkable letter with the hope that enlightened legislation will be so modified, arid the customs and consciences of individuals will be so altered, that any Utah gentleman, with more than the Christian number of wives, may be able to travel in any part of the United States with his harem and children, and enjoy as much consideration honor as the patriarch Jacob would have been re-spected had he, with his wives and children, paid a visit to his kindred. We have heard much of the 'good time coming,' probably it is the period the lady refers to.