When we have exhausted the various schools of Art--during which discussion the whole body have remained profoundly attentive, except when some unusual noise at the Theatre over the way, has induced some gentleman to glance inquiringly towards the window in that direction, behind his next neighbor's back--we burrow for information on such points as the following. Whether there really are any highway robberies in London, or whether some circumstances not convenient to be mentioned by the aggrieved party, usually precede the robberies complained of, under that head, which quite change their character? Certainly the latter, almost always. Whether in the case of robberies in houses, where servants are necessarily exposed to doubt, innocence under suspicion ever becomes so like guilt in appearance, that a good officer need be cautious how he judges it? Undoubtedly. Nothing is so common or deceptive as such appearances at first. Whether in a place of public amusement, a thief knows an officer, and an officer knows a thief,--supposing them, beforehand, strangers to each other--because each recognizes in the other, under all disguise, an inattention to what is going on, and a purpose that is not the purpose of being entertained? Yes. That's the way exactly. Whether it is reasonable or ridiculous to trust to the alleged experiences of thieves as narrated by themselves, in prisons, or penitentiaries, or anywhere? In general, nothing more absurd. Lying is their habit and their trade; and they would rather lie--even if they hadn't an interest in it, and didn't want to make themselves agreeable--than tell the truth. From these topics, we glide into a review of the most celebrated and horrible of the great crimes that have been committed within the last fifteen or twenty years. The men engaged in the discovery of almost all of them, and in the pursuit or apprehension of the murderers, are here, down to the very last instance. One of our guests gave chase to and boarded the Emigrant Ship, in which the murderess last hanged in London was supposed to have embarked. We learn from him that his errand was not announced to the passengers, who may have no idea of it to this hour. That he went below, with the captain, lamp in hand--it being dark, and the whole steerage abed and sea-sick--and engaged the Mrs. Manning who _was_ on board, in a conversation about her luggage, until she was, with no small pains, induced to raise her head, and turn her face towards the light. Satisfied that she was not the object of his search, he quietly re-embarked in the Government steamer alongside, and steamed home again with the intelligence. When we have exhausted these subjects, too, which occupy a considerable time in the discussion, two or three leave their chairs, whisper Sergeant Witchem, and resume their seats. Sergeant Witchem, leaning forward a little, and placing a hand on each of his legs, then modestly speaks as follows: