Philosophical experiments containing useful, and necessary instructions for such as undertake long voyages at sea. Shewing how sea-water may be made fresh and wholsome: and how fresh-water may be preserv'd sweet. How biscuit, corn, &c. may be secured from the weevel, meggots, and other insects. And flesh preserv'd in hot climates, by salting animals whole. To which is added, an account of several experiments and observations on Chalybeate or Steel-waters: with some attempts to convey them to distant places, preserving their virtue to a greater degree than has hitherto been done. Likewise a proposal for cleaning away mud, &c. out of rivers, harbours, and reservoirs