The Collaborative International Dictionary
Soap \Soap\, n. [OE. sope, AS. s[=a]pe; akin to D. zeep, G. seife, OHG. seifa, Icel. s[=a]pa, Sw. s?pa, Dan. s?be, and perhaps to AS. s[=i]pan to drip, MHG. s[=i]fen, and L. sebum tallow. Cf. 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 cf. Saponification. By extension, any compound of similar composition or properties, whether used as a cleaning agent or not.
Note: In general, soaps are of two classes, hard and soft. Calcium, magnesium, lead, etc., form soaps, but they are insoluble and useless.
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.
--Roscoe & Schorlemmer.
Castile soap, a fine-grained hard soap, white or mottled, made of olive oil and soda; -- called also Marseilles soap or Venetian soap.
Hard soap, any one of a great variety of soaps, of different ingredients and color, which are hard and compact. All solid soaps are of this class.
Lead soap, an insoluble, white, pliable soap made by saponifying an oil (olive oil) with lead oxide; -- used externally in medicine. Called also lead plaster, diachylon, etc.
Marine soap. See under Marine.
Pills of soap (Med.), pills containing soap and opium.
Potash soap, any soap made with potash, esp. the soft soaps, and a hard soap made from potash and castor oil.
Pumice soap, any hard soap charged with a gritty powder, as silica, alumina, powdered pumice, etc., which assists mechanically in the removal of dirt.
Resin soap, a yellow soap containing resin, -- used in bleaching.
Silicated soap, a cheap soap containing water glass (sodium silicate).
Soap bark. (Bot.) See Quillaia bark.
Soap bubble, a hollow iridescent globe, formed by blowing a film of soap suds from a pipe; figuratively, something attractive, but extremely unsubstantial.
This soap bubble of the metaphysicians.
--J. C. Shairp.
Soap cerate, a cerate formed of soap, olive oil, white wax, and the subacetate of lead, sometimes used as an application to allay inflammation.
Soap fat, the refuse fat of kitchens, slaughter houses, etc., used in making soap.
Soap liniment (Med.), a liniment containing soap, camphor, and alcohol.
Soap nut, the hard kernel or seed of the fruit of the soapberry tree, -- used for making beads, buttons, etc.
Soap plant (Bot.), one of several plants used in the place of soap, as the Chlorogalum pomeridianum, a California plant, the bulb of which, when stripped of its husk and rubbed on wet clothes, makes a thick lather, and smells not unlike new brown soap. It is called also soap apple, soap bulb, and soap weed.
Soap tree. (Bot.) Same as Soapberry tree.
Soda soap, a soap containing a sodium salt. The soda soaps are all hard soaps.
Soft soap, a soap of a gray or brownish yellow color, and of a slimy, jellylike consistence, made from potash or the lye from wood ashes. It is strongly alkaline and often contains glycerin, and is used in scouring wood, in cleansing linen, in dyehouses, etc. Figuratively, flattery; wheedling; blarney. [Colloq.]
Toilet soap, hard soap for the toilet, usually colored and perfumed.
n. (alternative form of diachylum English)
Diachylon (from Latin diachȳlōn, representing Greek , "[a medicament] composed of juices"), also rendered diachylum or diaculum, was originally a kind of medicament made of the juices of several plants (thus its name), but now commonly the name for lead- plaster, emplastrum plumbi—a plaster made of lead oxide boiled together with olive oil and water. It is applied to sheets of linen, and works as an adhesive plaster when heated.
Historically, several different types of diachylons have been described. White, or simple, diacyhlon is compounded of common oil, litharge of gold ( litharge mixed with red lead), and adhesives drawn from the root of the Althaea, the seeds of flax and fenugreek. The diachylon called direatum has for its basis the common white diachylon, but with every pound of which is mixed an ounce of powder of Iris; this plaster digests, incides, and ripens with more force than the simple diachylon.
There is also the great diachylon, or diachylon magnum, composed of litharge of gold, oils of iris, chamomile, and aneth, turpentine, pine resin, yellow wax, and adhesives derived from flax, fenugreek, with new figs, raisins of Damascus, icthyocolla, juices of iris, squill, and hyssop. This diachylon was said to soften hard swellings called scirrhus, and dissipate tumors.
The diachylon gummatum is the great diachylon with the addition of gum ammoniac, galbanum, and sagapenum, dissolved with wine, and boiled to a consistency of honey. This plaster was believed the most power of all for digesting, ripening, and resolving.