S O A

SO A

( 325 )

extent with water. Adipocire likewife is a fapo--naceous fubftance, being diffufible in water, andto a certain degree foluble in it by means of theammonia ainited to the oily matter. Milk onthe other hand is not faponacoous though it.•contains an oil diffufed in a watery ferum, asthe intermede by which this is effected is (toall appearance) not faline, but albuminous and.infipid.

But the term foap is in common languagereltridted to that combination of oil with alkaliwhich is extenfively ufed ifor domeftic and.manufacturing purpofes.

The materials ufed in foap making.are, oilof any kind, vegetable or animal, and fixedalkali, either foda or potalh. Thefe (that is,oil and alkali,) enter into the compofition ofevery foap, and hefides, lime is effential to givefhe alkali the requifite degree of caufticity:common fait is alfo employed in moft of thepotafh-foaps, for a purpofe which will be after-wards mentioned.

The general procefs for foap-making is on(he whole very Ample, and confifts, firft inmaking a cauftic or partly cauftic ley with thealkali and lime; next of boiling the ley with theoil till they are perfedly united into a fmoothUniform foapj and laftly of drying the foap tillit is become of a proper confidence for ufe.But though the general procefs is fimple, andfuccefs to a certain degree may be infured byany one who puts the proper ingredients to-gether in the plained manner, there are aconfnjerable number of precautions and manyminute attentions required to make the bed andmod perfe# article with the greated economy.Mod of thefe are only to be learnt by pradicalexperience, but it will be proper in this placeto enlarge upon the different deps and varietiesof this very important manufacture.

The fimpled, and on the whole the modbeautiful foap, is the fine white foap preparedfrom olive oil and foda, extraded from the bedbarilla, which .is manufactured very largely inthe.countries where the olive grows, efpeciallyin the South pf France , (for which Marfeiliesis the mod celebrated) in fome parts of Italy ,and in Tripoli, which laft ;is often of excellentquality and cheap, and is largely imported intovarious parts of Europe . A.fimilar, hut moreexpenfive foap is made .of fpda and oil of al-monds, for medicinal purpofes. What is calledin this country Windfor foap is of (this kind,with either of the above mentioned .oils.

But the common foaps ufod in England are

.* .Wemoircs dc Pelletier.

made, as to the oil, principally of tallow andany other candle or kitchen greafe, and as tothe alkali, of,potalh, pearlalh, and other kindsof the vegetable alkali, with or without amixture of barilla, according to the price of thelatter; and on account of the peculiar ufe ofcommon fait in moft of them, the procefs isfomewhat more complicated. The ordinaryyellow foap alfo differs from the white , in con-taining a portion of rofin, and fometimes alfois icented with palm oil.

We fhall iirft deferibe the method of makingthe white olive oil foap, which with fome littlevariations is pra&ifed at Marfeilles, and otherparts of France . abc

To make about 1000 lbs. of this foap thematerials requifite are 500 lbs. of good barilla,600 lbs. of olive oil, (of which the inferiorforts are ufed, and anfwer .full as well) and 100lbs. of quicklime. The barilla Being firftbroken down in a mill to a coarfe powder, andthe lime flacked with a little water and lifted,they are ftirred together and put into a vat witha perforated bottom, and covered a few incheswith water, to extra# the alkali. In two orthree days the ftop-cock at the bottom of thevat is opened, and x clear, nearly cauftic, ftrongley of foda is drawn off. It Ihould be fo muchconcentrated that a frelh egg will fwim in it,and is about of that fpecific gravity that elevendrams of it in weight will only fill a bottlewhich would contain an ounce or eight dramsof water. When all this ley is drawn off, thecock is turned, frelh water is poured on thematerials, and after Handing for fome hoursthe ley is drawn off as before. This fecond leyis Hill very alkaline, but much weaker than thefirft. A third ley is generally prepared in thefame way, which is ftill weaker. The materials,which are now exhaufted of their alkali andconfift of carbonat of Lime with the impuritiesof the barilla, are ufed as manure.

The oil is then poured into the boiler (whichis a large copper veflel, fet in brick work, andheated by a furnace under its bottom; and withit the third or weakeft ley, and the fire iskindled and raifed till the liquor begins to boil.The materials are conftantly ilirxed to haften theunion between the oil and the alkali, and the reftof the third and the fecond leys are addedgradually. As foon as the liquor in the boilerbegins to get hot it turns milky, and after fomehours boiling will be found to become moretenacious and thicker. Then a fmall portion ofthe firft or ftrongeft ley is thrown in, and this

Bcaume Siemens de Pharmacie.

‘ Encycl. Arts and Metiers, article Savon,