6. Table exhibiting in degrees of Fahrenheit the Boiling Heat of different liquids

6. Table exhibiting in degrees of Fahrenheit the Boiling Heat of different liquids.

Ether.............................96°

do sp. grav.: .7365 at 48°........100

Carburet of Sulphur................113

Alcohol, sp. gr. .813................1731/2

Nitric Acid, sp. gr. 1.42............247

Water.............................212

Ammonia..........................140

Muriatic Acid, sp.gr. 1.094.........232

Rectified Petroleum................306

Oil of Turpentine..................316

Sulphuric Acid, sp. gr. 1.848........600 do        do do 1.810........473 do        do do 1.780. .....435 do        do do 1.700........374 do        do do 1.650........350 do do do 1.520........290 do do do 1.300........240

Phosphorus........................554

Linseed Oil........................640

Whale Oil.........................630

Mercury...........................662

7. Table showing the Boiling Heat of various Saturated Solutions

7. Table showing the Boiling Heat of various Saturated Solutions. Saturated solution of

Muriate of Lime.................285°

Acetate of Soda.................256

Nitrate of Soda..................246

Rochelle Salt....................240

Nitre...........................238

Muriate of Ammonia.............236

Tartrate of Potash...............234

Sea Salt........................2241/2

Muriate of Soda.................224

Sulphate of Magnesia............222

Borax...........................222

Phosphate of Soda...............222

Carbonate of Soda...............220

Alum...........................220

Chlorate of Potash...............218

Sulphate of Copper..............216

Acetate of Lead.................2152/3

Glauber Salt....................2131/2

8. Concentration

8.    Concentration. The volatilization or evaporation of part of a liquid in order to increase the strength of the remainder. The operation can only be performed on solutions of substances of greater fixity than the menstrua or liquids in which they are dissolved. Many of the liquid acids, solutions of the alkalis, etc., are concentrated by distilling off their water.

9. Crystallization

9.    Crystallization. Crystals are symmetrical forms assumed by certain bodies in solidifying from a liquid or gaseous state: and as the same substances, under similar circumstances, always assume the same crystalline shape, their crystals afford a means of distinguishing substances otherwise similar in appearance; as for instance oxalic acid and Epsom salts. Sulphur, anhydrous salts, lead, tin, and other fusible substances which are unalterable by heat are crystallized by fusion. They are to be melted at the lowest possible temperature, and allowed to cool very gradually. As soon as a crust forms on the surface (which then becomes furrowed) it must be pierced with a rod, and the fluid portion decanted, and the crystals will be found coating the interior of the vessel. Volatile solids, such as iodine, camphor, etc., when heated so as to produce Sublimation (see No. 30 (Sublimation)), yield vapors which, in cooling, take the form of crystals.

Soluble substances are crystallized by the evaporation of a saturated solution of the substance. The solution should be made and, if necessary, clarified and filtered at boiling point, in which state more of the substance is eld in solution than when cool; this excess is deposited in crystalline form as the solution cools or evaporates. The crystals thus obtained are strained from the remaining liquid, or mother water, and dried.

If strings be suspended in the hot solution, crystals will form upon them during cooling or evaporation; in this manner rock-candy, blue vitriol (sulphate of copper), alum, etc., are crystallized. Crystallization is also sometimes the result of chemical reaction; silver, for instance, precipitated from its solutions by zinc, forms a crystalline deposit.