A Treatise On Adulterations of Food, And Culinary Poisons

OOD WATER. A Good criterion of the purity of water fit for domestic purposes, is its softness. This quality is at once obvious by the touch, if we only wash our hands in it with soap. Good water should be beautifully transparent : a slight opacity indicates extraneousmatter. To judge of the perfect transparency of water, a quantity of it should be put into a deep glass vessel, the larger the better, so that we can look down perpendicularly into a considerable mass of the fluid; we may then readily discover the slightest degree of muddiness much better than if the water be viewed through the glass placed between the eye and the light. It should be perfectly colourless, devoid of odour, and its taste soft and agreeable. It should send out air-bubbles when poured from one vessel into another; it should boil pulse soft, and form with soap an uniform opaline fluid, which does not separate after standing for several hours. It is to the presence of common air and carbonic acid gas that common water owesits taste, and many of the good effects which it produces on animals and vegetables. Spring water, which contains more air, has a more lively taste than river water. Hence the insipid or vapid taste of newly boiled water, from which these gases are expelled : fish cannot live in water deprived of those elastic fluids. 100 cubic inches of the New River water, with which part of this metropolis is supplied, contains 2,25 of carbonic acid, and 1,25 of common air. ...