143. Method of making putrid Water sweet in a Night's Time.—Four large spoonfuls of unslaked lime put into a puncheon of ninety gallons of putrid water, at sea, will, in one night, make it as clear and sweet as the best spring water just drawn: but unless the water is afterwards ventilated sufficiently to carbonize the lime, it will be a lime water. Three ounces of pure unslaked lime should saturate ninety gallons of water.
144. Lead Cisterns.—Lead Cisterns are unsafe to hold water for culinary purposes: if the water has stood in them several days undisturbed, a small white coating may be observed at the upper edge of the water: on any addition of water, this coating is washed off, and if there be the slightest acidity in the vessel, this coating will be dissolved in the water, and thus a poison be conveyed into the stomach. To prevent this, the insides of lead cisterns should be occasionally examined and cleared out.
145. To prevent the freezing of Water in Pipes in the Winter Time.—By tying up the ball-cock with straw or flannel during the frost, the freezing of pipes will often be prevented; in fact, it will always be prevented where the main pipe is higher than the cistern or other reservoir, and the pipe is laid in a regular inclination from one to the other, for then no water can remain in the pipe; or if the main is lower than the cistern, and the pipe regularly inclines, upon the supply's ceasing, the pipe will immediately exhaust itself. When water is in the pipes, if each cock be left a little dripping, the circulation of the water will prevent its freezing in the pipes.
146. To preserve Water and Meat from Putrefaction in long Voyages.—The crews of two Russian ships, which sailed round the world, were extremely healthy. During the whole three years of their voyage only two men died of the crew of the Neva, and the Naveshda did not lose a single man. It is known that their fresh water was preserved in charred casks, but it is not so generally known that they used the same precaution for preserving their salted provisions. The beef they carried out with them tasted as pleasantly upon their return, as it did three years before, when first salted.
147. To make Sea-water fit for washing Linen.—Soda put into sea-water renders it turbid; the lime and magnesia fall to the bottom. Therefore, to make sea-water fit for washing linen, put in soda enough as not only to effect a precipitation of these earths, but to render the water sufficiently alkaline.