Page:The New International Encyclopædia 1st ed. v. 18.djvu/336

SNOWY OWL. 283 SOAP. ptarmigan. Many curious superstitions cling about it in the folk-lore of the northern peoples. SNtJFF. See Tobacco. SNTJFF-TAKERS. See Conscience Whigs. SNY'DERS, Frans (1579-16.57). A Flemish painter, born at Antwerp. He studied under Pieter Brueghel the younger and Hendrick van Balen. His talents won for him the admiration of Rubens, who fi'equently engaged him to paint fruit, game, and other accessories in his pictures ; and in turn Rubens often contributed the figures to the canvases of Snyders. The chief works which they painted together are "Diana's Hunt" (Berlin Museum) and the "Prometheus and the Eagle" (Oldenburg Museum). As a painter of hunting episodes, scenes of violent action, and combats of animals, Snyders stands as very nearly tlie equal of Rubens. His pictures are seen in all the famous galleries of Europe, that of Madrid possessing no less than twenty-one. There are five of his pictures at the Stockholm Museum : fourteen at the Hermitage, Saint Petersburg: ten at Dresden: and seven at Munich. Among those at Munich is his master- piece, 'Two Lions Pursuing a Roebuck." A sub- ject quite similar was bequeathed to the Metro- politan Museum, New York City, in 1871. SOANE, son, Sir John (1753-1837). An English arehitect. born at White Church, near Reading. In 1788 he was appointed architect to the Bank of England, which remains the best example of his woi'k. He was elected to the Royal Academy in 1802. and became professor of architecture there in 1800. While lecturing he began the foundation of the Soane Museum, which he left to the British nation. It contains a valuable collection of pictures, casts, and an- tiquities. His written works include Designs for Public Im/n-ovemenfs in London and Westminster (1827). and Desiffns for Puhlic and Private Buildings (1828). " SOAP (AS. sSpe, OHG. seifa, seipfa. Ger. Seifc, soap; probably connected with AS. sipnn, MHG. slfen. to drip, trickle. Lat. sehiim. tallow). A term generally employed in chemistry to de- scribe the metallic salts of the higher fatty acids. In commerce it has a more limited application, being confined to the potassium and sodiiun salts which are extensively used as detergents. These soaps are also used in a limited way as bases for various dyestuffs. and sometimes for medical purposes. The sodium compovmds of fatty acids, being generally efflorescent, harden on exposure to air, and hence are known as hard soaps. The potassiimi compounds, on the contrary, absorb water un<ler the same conditions and consequent- ly tend to liquefy; hence the.v are called soft soaps. The fats generally used in soap-making include various tallows and greases of animal origin, lard oil, palm oil, olive oil. cotton-.seed oil, corn oil, eocoanut oil, stearin, red oil (crude oleic acid ) , etc. The alkali lyes are pre- pared either by dissolving caustic soda or potash in water to the desired strength, or, as is more often the case in large establishments, at least with the caustic soda lyes, they are made by dissolving carbonate of soda in hot water and then adding the requisite quantity of quicklime for causticizing, boiling and allowing the mass to cool, when the clear lye is drawn from the top. The solution thus obtained is often strengthened by evaporation or by addition of a further quan- tity of solid caustic alkali. The soaps manufactured at present may be classified as follows: (1) Rosin or laundry, set- tled soaps; (2) toilet soaps, including settled, half-boih'd, transparent, and floating varieties; (3) marine soaps; (4) medicated soaps; and (5) manufacturing soaps. The materials required in manufacturing set- tled soaps include tallow (alone or mixed with grease and oil), caustic soda solution (18°-22° Baume), and pickle (saturated salt solution). The operation is carried out in large sheet-iron kettles, circular or square in section, and heated by two steam coils l.ving on the bottom of the kettle. One coil is perforated with small holes and delivers free steam in fine jets (the 'open coil') ; the other serves to heat the contents of the kettle but allows no escape of steam (the 'closed coir ) . The various operations are known as stock change, rosin change, strength change, and finish stock change. The 'stock' (i.e. the fatty material) is pumped in liquid state into the kettle and partly spent l,^e from a previous operation is added, the open coil being used as a heater. A portion of the stock being always somewhat rancid, it unites at once with the lye to form soap, the soap in turn, with the aid of the live steam, emulsifying the rest of the fat. The open coil is now shut and the closed coil used, i'rom time to time addition of strong fresh lye is made until the contents of the kettle are homogeneous, have a characteristic gummy appearance, and run in long strings from a wooden paddle hich has been dipped in the hot liquiil. Pickle is now added until the soap becomes insoluble ('grained') and floats on the surface. The contents of the kettle, being al- lowed to cool, separate into two layers, the granular imperfect soap floating on the brine. The latter, which contains glycerin, is drawn off from the bottom of the kettle and worked for glycerin and salt. To the soap remaining in the kettle is added fresh strong lye and rosin to the amount of 50 to 100 per cent, of the stock originally used. This mixture is heated by the closed coil until the rosin is saponified and then the kettle is salted out as before. On standing, a lye separates which contains a little glycerin not extracted in the previous process; this lye, too, is worked for its glycerin and salt. The next operation (the 'strength change') is introduced in order to insure complete saponification. For this purpose fresh strong lye (at least 22° Baume) is added and the mass is kept gently boiling for several hours in the grained condition, strong l,ye having the same effect on soap as pickle ; viz. it renders the soap insoluble. At the conclusion of this operation the kettle contents are allowed to cool and se'ttle, and the drawn off lye. which is not exhausted as in the previous operations, is used to start a new saponification in the stock change. The grained soap is finally reheated and enough cold water added to cause it to pass into solution ('close'). At this stage the heat is turned off, and the kettle contents slowly cool down and stratify in three layers: the soap on top. next an impure dark soap called 'nigre,' and finally a small quantity of strong dark lye too impure for further use. The process of making settled soap without rosin is the same, except that the