Soap
Soap , noun
[Old English sope, Anglo-Saxon sāpe; akin to Dutch zeep, German seife, Old High German seifa, Icelandic sāpa, Swedish s{not transcribed}pa, Danish s{not transcribed}be, and perhaps to Anglo-Saxon sīpan to drip, Middle High German sīfen, and Latin sebum tallow. Compare Saponaceous.]
A substance which dissolves in water, thus forming a lather, and is used as a cleansing agent. Soap is produced by combining fats or oils with alkalies or alkaline earths, usually by boiling, and consists of salts of sodium, potassium, etc., with the fatty acids (oleic, stearic, palmitic, etc.). See the Note below, and compare Saponification. By extension, any compound of similar composition or properties, whether used as a cleaning agent or not.
The purifying action of soap depends upon the fact that it is decomposed by a large quantity of water into free alkali and an insoluble acid salt. The first of these takes away the fatty dirt on washing, and the latter forms the soap lather which envelops the greasy matter and thus tends to remove it.
This soap bubble of the metaphysicians.
In general, soaps are of two classes, hard and soft. Calcium, magnesium, lead, etc., form soaps, but they are insoluble and useless.
Soap , transitive verb
1.
To rub or wash over with soap.
2.
To flatter; to wheedle. [Slang]