Instinct, or experience, has made even the horse himself conscious of this ; for he will never drink hard water, if he has access to soft ; he will leave the most transparent water of the well, for the river, although the water may be turbid, and

water can be easily freed from these earthy salts ; boiling precipitates the carbonate

of lime by driving off the carbonic acid which holds it in solution ; and the addition of a little carbonate of soda precipitates the lime, if any exist in the water. Many persons prefer the taste of hard water to that of soft, and a change from one to the

other, frequently causes a derangement of the digestive organs. The briskness, and rapidity of this and other water is owing to the air, and carbonic acid mixed with it.

The air contained in water, has a larger proportion of oxygen than atmospheric air, and hence it is better adapted for the respiration of animals. The water procured from wells in the city of New- York, has gradually been growing more and more impure, as the city has increased in size, until a very large proportion of it, is entirely unfit for culinary and dietetic purposes. That in the

lower part of the city, has always been, more or less, brackish, owing to the percolation of the salt water from the north and east rivers through the loose sandy soil, thus giving them a distinct saline impregnation. The amount of impurities contained in these waters, varies, therefore, in different parts of the city, according to its elevation, and the denseness of the population. A gallon of water from the well belonging to the Manhattan Company in Reade-street, yielded 125 grains of solid matter ; while the same quantity of water, from their well in Bleecker-street, yielded 20 grains, and in 13th street, 14 grains.