MAKING SOAP

New Zealand Mail, 15 February 1900, Page 8

MAKING SOAP

The kind of fat used depend- .. particular kind.of soap ’ may be divided into curd soap, softsoap, and scer.fea so! soap is a compound in definite P S (: A11 ot some oil, tat, or resin with Y°P or b°ns ing base, which musf bTaika inf tended to use the soap for cWnsW 810 ’ poses, inasmuch as tne tomnnS metallic oxides, lime, aud T°l Ud ! soluble in water. Pats ire solid substance calle<i stearine, one denominated elaine. Wlien-eitW f these is boiled with a strong sofulihs caustic potash or soda a takes place called saponification. TkeS duct is a viscid, homogeneous, and K parent mass, ireely soluble in warm fir and partially so in cold, but insoluK saline solutions, 'vhen any common (at is treated with a hot ley of potash or sods a solid pearly matter, margaric acid,’ami t;H Uld i, ° ie .n acid > enter into combination with the alkali, while a third matter tha glycerine, or sweet principle, as it usiri to be called, remains free and dissolved in the mother-liquor. Common soap is a mixture of an alkaline margarato and oleate in proportions varying with the peculiar kind ot fat employed. Soap formed'with vegetable oil is chiefly an oleate, whilst that made with tallow is on the contrary almost entirely a margarate. All fats do not saponify equally well, the best being oil of olives and almonds, next to which rank in the order in which they are enumerated— hog’s lard and tallow, colza oil, PpPPy oii, fish oils, hempseed oil, linseed oil, palm oil, and resin. Soft soap is a compound of potash ar.d fat or oil. Three kinds arc known in commerce, viz., common soft soap, which is made with coarse hsa oil; green scap, made with vegetable oils, such as rape and poppy oil; and white sett soap, the produce of the mixture of Potash and allow’. In the manufacture of the common and green soaps, the. art consists-in the combination of the oil with the potash without the soap ceasing to be dissolved in the ley; while, on the contrary, in the fabrication of hard soap, it is necessary to separate the soap from the ley, even before the saturation of the ley is accomplished. But soft soap contains mere alkali than is absolutely necessary for the saponification of the oily matter, and is really a perfect soap dissolved in an alkaline mother liquor. It may readily be converted into hard soap by the addition of common salt. Toilet soaps are made with oil, or 6iiet, saponified either with soda or oil. or suet, saponified either with soda or potash, according as they are desired to be hard or soft, and with as little excess of alkali as possible. Glycerine is now artificially combined with these soaps, instead of being wholly removed in the mother liquor; but the process if a diilieult.-one; and it is even said to be impossible. Honey has been used for the same purpose,-that is, to soften the skin; but there is p® doubt that if glycerine can really h®,* 8 / corporated with the soap, it ought to exert a very mollifying effect upon the skin, if it remains in the condition of pure’Kff’ cerine as obtained in the usual way-—' ."Farm, Field, and Fireside.’’ -Y