A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

iS SEA WATER DISTILLATION. of the two gases, hydrogen and oxygen, in the pro- portion of 2 atoms of hydrogen (whose atomic weight is 1) to 1 atom of oxygen (whose atomic weight is 16), so that, weight for weight, water (FLO) is composed of 1 part of hydrogen and 8 parts of oxygen. These gases are chemically combined in this ratio, whether the combina- tion is in a solid state (ice), a liquid state (water), or a gaseous state (steam), and the absorption of heat changes the state of this combination of the two elements which may be solid, liquid, or gaseous ; whilst the loss of heat exactly reverses the operation—i.e., changes it from steam to water, then to ice, without changing its composition. 4. The saline matter of all seas and oceans consists mostly of what is commonly called salt—that is, common salt, chemically called chloride of sodium, or muriate of soda, as it used to be commercially called. But although this is the predominating salt, many others are more or less strongly in evidence, whilst there are traces of a still larger number of other salts. The “ bay-salt ” of commerce is the saline matter of the sea water evapor- ated at a very low heat, and the brine or concentrated form of sea water is also known under the name of “ bittern.” Note.—The information we have respecting the composi- tion of sea water is mostly derived from the researches of eminent analysts, such as Schweitzer, Usiglio, Dittmar, and others. There is also the very elaborate paper by Forchhammer in the JR. S. Phil. Trans. (1865). The reports of the investigations made by the officers of H.M.S. “ Challenger ” also give much information on this subject. 5. From these reports we find that besides the presence