In addition to the economic progress to which we alluded at the outset, serious considerations as to the public health are attached to this immense question,--the drainage of Paris. Paris is situated between two sheets,--a sheet of water and a sheet of air. The sheet of water, lying at a very great depth, but already tapped by two borings, is supplied by the stratum of green sandstone situated between the chalk and the Jurassic limestone; this stratum may be represented by a disc with a radius of twenty-five leagues; a multitude of rivers and streams drip into it, and the Seine, the Marne, the Yonne, the Oisin, the Aisne, the Cher, the Vienne, and the Loire are drunk in a glass of water from the Grenelle well. The sheet of water is salubrious, for it comes from the sky first, and then from the earth; but the sheet of air is unhealthy, for it comes from the sewer. All the miasmas of the cloaca are mingled with the breathing of the city; hence this bad breath. The atmosphere taken from above a dungheap, it has been proved scientifically, is purer than the atmosphere taken from over Paris. Within a given time, by the aid of progress, improvements in machinery, and enlightenment, the sheet of water will be employed to purify the sheet of air, that is to say, to wash the sewer. It is known that by washing the sewer we mean restoring the ordure to the earth by sending dung to the arable lands and manure to the grass lands. Through this simple fact there will be for the whole social community a diminution of wretchedness and an augmentation of health. At the present hour the radiation of the diseases of Paris extends for fifty leagues round the Louvre, taken as the axle of this pestilential wheel. We might say that for the last ten centuries the cloaca has been the misery of Paris, and the sewer is the viciousness which the city has in its blood. The popular instinct has never been deceived, and the trade of the sewer-man was formerly almost as dangerous and almost as repulsive to the people as that of the horse-slaughterer, which so long was regarded with horror and left to the hangman. Great wages were required to induce a bricklayer to disappear in this fetid sap; the ladder of the well-digger hesitated to plunge into it. It was said proverbially, "Going into the sewer is entering the tomb;" and all sorts of hideous legends, as we said, covered this colossal cesspool with terrors. It is a formidable fosse which bears traces of the revolutions of the globe as well as the revolutions of men; and vestiges may be found there of every cataclysm from the shells of the Deluge to the ragged sheet of Marat. BOOK III. MUD, BUT SOUL. CHAPTER I. THE CLOACA AND THE SURPRISES.