It was Saturday morning; and with my professional habits, I naturally thought of the many divines in that very city, who were at that moment shut up in their studies, preparing their discourses for the morrow. I wished I had them all before me. I could have given every one of them a text to preach upon. I would have said, "Gentlemen, see there! and blush for your fellow-citizens. See there! and never again talk of American liberty. See there! and lift up your voices like so many trumpets against this enormity. See there! and in the face of persecution, poverty, imprisonment, and (if needs be) even death itself, bear your faithful testimony, and cease not until this foul stain be wiped away from your national escutcheon. Dr. S----, to-morrow morning let this be your text,--'Where is Abel, thy brother?' Dr. II----, let your discourse be founded on Exod. xxi. 16: 'And he that stealeth a man, and selleth him, or if he be found in his hand, he shall surely be put to death.' You, the Rev. Mr. C----, let your gay and wealthy congregation be edified with a solemn and impressive sermon on Is. lviii. 6: 'Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?' And you, the Rev. Mr. H----, let your hearers have a full and faithful exposition of that law which is 'fulfilled in one word, even in this, Thou shalt love thy neighbour as thyself.'" In the afternoon of the same day, as I walked along one of the principal streets, I saw a flag issue from a fine large public building to invite "ladies and gentlemen" to see "the magnificent picture of the departure of the Israelites from Egypt,"--the canvas containing 2,000 square feet, and 2,000,000 of figures! How significant! It would have been still more so, if the number of "figures" had been 3,000,000 instead of 2,000,000. What an "abolition" picture! It must have been worse than "Jacob and his Sons," which was expunged from a catalogue of the American Sunday-School Union, because, in reprehending the sale of Joseph to the merchants, it reflected upon the _internal_ slave-trade! Surely such exhibitions will affect the safety of the "peculiar institution!" LETTER IV. A Sabbath in New Orleans--The First Presbyterian Church--Expectoration --A Negro Pew--The Sermon.