almost entirely of lentil-powder, barley-flour, &c., which are charged cent. per cent. above their real value. Of all the articles we have touched upon, not one is so important as water. It mixes more or less with all our solid food, and forms nine-tenths of all our drinks. Man himself, as a sanitary writer has observed, is in great part made up of this element, and if you were to put him under a press you would squeeze out of him 8-1/2 pailfuls. That it should be furnished pure to the consumer is of the first importance in a sanitary and economic point of view. We are afraid, however, that but feeble attempts have been made to secure this advantage to the metropolis. At present London, with its two and a half millions of population, is mainly supplied by nine water companies, six of which derive their supply from the Thames, one from the New River, one from the Ravensbourne, and a third from ponds and wells. Besides this supply, which ramifies like a network over the whole metropolis, we find dotted about both public and private wells of various qualities. We do not intend to follow Dr. Hassall into his microscopic representations of the organic matter, vegetable and animal, by which the customers of one company can compare the water served to them with that dealt out to others, and thus at a glance assure themselves that they have not more than their share of many-legged, countless-jointed, hideous animalculæ, which look formidable enough to frighten one from ever touching a drop of London water, but shall content ourselves with giving the general characteristics of the whole of them. With one exception they were all of a hardness ranging from 11 to 18 degrees. This hardness depends upon the earthy salts present, such as sulphates and bicarbonates of lime and magnesia. They were also to some extent saline, as all the salt used in the metropolis ultimately finds its way into the Thames, or great sewer-stream. Not long ago two, at least, of these six Thames water companies procured their supply within a short distance of the mouths of great drains, and all of them resorted to the river at different points below Battersea, or that portion of it which receives the drainage of the metropolis, and is consequently crowded with animal and vegetable matter, both living and dead, and thick with the mud stirred up by the passage to and fro of the steamers. The violent outcry made, however, by the Board of Health, caused an Act to be passed by parliament against the supply of the sewage rates, and now all the companies taking their supplies from the Thames, are compelled to go at least as high as Kingston, and to submit them to a process of filtration; but even at this point the river is in some degree sewage-tainted, and the chemically-combined portion of baser matter cannot be removed by any filter.