It has no effect upon unreasoning John Bull to tell him that, on an average, cholera does not devour a tithe of the victims which fever, consumption, and other preventible diseases make away with. Cholera comes upon him like an ogre, eating its victims all at once, and he quakes with terror; the daily, deadly destruction of human beings by “every-day” diseases, he takes no heed of. Take him, however, a slate and pencil; count costs to him; show that cholera costs so much; that ordinary, contagious, but preventible diseases, cost so much more; and that prevention is so many hundred per cent. cheaper than the cheapest cures, he begins to be amenable to reason. Nothing but pocket arithmetic, terror, or melo-dramatic appeals to his soft-hearted sympathy, moves John Bull. In order to supply the best of these exercitations by the accumulation of carefully sifted, and well authenticated facts, and sound reasonings; the results of scientific investigations, and of a large range of pathological statistics, the Metropolitan Sanitary Association has been for some months—like another “Ole Joe”—knocking at the door of Old John. Whether the heavy old gentleman will soon open it to conviction and improvement depends, we think, very much upon the energy and liberality with which that society is supported and seconded by the public; for whose sole benefit it was called into existence. To the exertions of many of its leading members, if not to the collective body itself, John Bull has responded, by admitting into his premises the Extra-Mural Interment Bill, and we think he is just now holding his door a-jar to catch the Water Supply Bill, which it is hoped he will admit, and pass through That House next session. Meantime we, in common with the association aforesaid, beg his attention to a few other points of improvement:—