Alcohol is one of the most useful of solvents, both for organic and inorganic substances, but especially the former. It dissolves balsams, essential oils, esters, fatty acids, hydrocarbons, resins, soaps, sugars, most vegetable alkaloids, and a large number of pharmaceutical drugs such as acetanilide, camphor, chloralamide, phenacetin, and phenazone. The fixed oils and fats are but sparingly soluble in alcohol, a notable exception, however, being castor oil, which is readily dissolved. As regards inorganic substances, alcohol dissolves the hydroxides of the alkali metals, but not the carbonates. Ammonium chloride, and indeed most of the chlorides which are readily soluble in water, are dissolved by alcohol. The following table of the solubility of various alkali halides in methyl and ethyl alcohols is due to Turner and Bissett: . 1

1 G. Chavanne, Bull Soc. chim. Belg., 1913, 27, 205.

2 Wade and Finnemore, Trans. Chem. Soc, 1904, 85, 946.

3 Analyst, 1916, 41, 334.

Grams of anhydrous salt dissolved by 100 grams of the alcohols at 25°.

Methyl alcohol.

Ethyl alcohol.

Lithium chloride .................................

42.36

25.83

,, iodide .................................

343.40

250.80

Sodium chloride .................................

1.31

0.065

„ iodide .................................

90.35

46.02

Potassium chloride .................................

0.53

0.022

,, bromide.................................

2.17

0.142

,, iodide.................................

18.04

2.16

Rubidium chloride.................................

1.41

0.078

Some of the metallic nitrates are dissolved by alcohol; the sulphates are generally insoluble. Deliquescent salts are usually soluble in alcohol, potassium carbonate being a notable exception to this rule, while salts which effloresce are mostly insoluble. Sulphur and phosphorus are dissolved to a small extent, and iodine freely. Many gases are more soluble in alcohol than in water; thus 100 volumes of alcohol dissolve 7 volumes of hydrogen, 25 of oxygen, and 13 of nitrogen.

Aqueous alcohol gives a turbid mixture with chloroform unless the proportion reaches a certain value, depending on the strength of the alcohol. According to K. Enz,2 the following proportions of alcohol at different concentrations are necessary for giving a clear mixture with 10 parts of chloroform: -

Sp. gr. of alcohol.

Parts of alcohol for 10 parts of chloroform.

0.834 ......

3.0

0.830 ............................

2.2

0.820 ......

0.93

0.818 ......

0.87

0.814 ......

0.43

0.812 ......

0.32

The alkali.metals dissolve in alcohol to form ethylates (so-called "alcoholates"), e.g., sodium ethylate, C2H5ONa.

Alcohol forms crystalline compounds with certain salts, e.g., calcium chloride, magnesium chloride, appearing as ' alcohol of crystallisation " in these compounds - CaCl2,4C2H6O, for example.

1 Trans. Chem. Soc, 103, 1913, 1904.

2 J. Soc. Chem. Ind., 1913, 32, 1169 (Abst.).