The Moral Temple of New-York—"Uncle Tom's Cabin." What a complete revolution has been worked by Manager PURDY, of the National Theatre! This place, previous to his taking it, was considered the lowest of any in New-York; but what a reformation has taken place! Thousands, who never would enter a theatre, (even the most aristocratic one,) now visit the National. It has become a perfect temple—a powerful instrument in the promotion of Religion and Morality,—a place recommended and attended by our clergy and their flocks, and where all can be benefited by the truths there inculcated. Go this afternoon and see "The Hot Corn Girl," or to-night and witness "Uncle Tom's Cabin," and then say if our assertions are not true.