Britain at Work
A Pictorial Description of Our National Industries

SOAP-MAKING. 247 linseed, cotton seed, etc. : the very mention of such names seems to bring us into contact with the most distant and some of the least inviting parts of the world. Resin is another ingredient which has the effect of rendering the soap more readily soluble, and helps to raise a pleasant lather. The preparation of these various ingre- dients for the soap manufacturer are industries in themselves, though in some cases oil factories are run in connection with soap- making works. Generally, however, it may be said that the manufacturer buys his materials ready for mixing. They are carried in barrels, out of which the soap-maker melts the fat by means of jets of steam. The liquid is then run into tanks, where all im- purities are carefully removed. The next stage is the all-important one of boiling ; and here we get in touch with the actual working. Enter, then, the boiling room. The atmosphere is hot and humid and fragrant, reminiscent somewhat of washing- day. The huge square pans, each capable of holding some sixty tons of material, are ranged in a double row. Some, you observe, are empty, save for a thickish remnant like a yellow scum that bubbles slowly and sullenly. Standing by each of the full pans is a very warm and watchful attendant armed with a long spoon—a very long spoon indeed. With this from time to time he stirs the steaming mass, which bears a striking resemblance to butter-scotch, and at in- tervals he throws in a few shovelfuls of salt from a heap by his side. To ■the eye of the outside observer, there is not much that is illuminating in’ watching the boiling process. Only to the expert are the signs of gradual saponification easily apparent. Probably what strikes the outsider most is the curious de- meanour of the soap at this stage. For a moment, perhaps, the mass of yellow matter steams quietly with scarce a tremor ; then suddenly a crater opens in the centre of the pan and a violent eruption ensues, the splashes of lava, alias boiling soap, falling with an angry flop. Tending a pan is not, however, a dangerous occupation, though it calls for constant care and alertness. The heat for boiling purposes is nowadays almost universally applied by steam injected directly into the pans through a coil of perforated pipes, one of the advantages of this method being that the steam keeps the contents of the pan continually in motion. There are in the boiling of ordinary hard soap actually three stages. After the first boiling, which completes the saponification of the fat, salt is thrown in to separate the glycerine and other impurities. Steam is then shut off, and the contents are allowed to settle. The impurities fall to the bottom, and are drained off. This done, a little water, resin, and more soda or potash are added. When the resin has been saponified, salt is again thrown in, again the contents are allowed to settle, and the impurities are drained off. Then follows another boiling with soda or potash, and the soap may be said to be made, the whole process having occupied about a week. Still there is much to be done before the lady receives her stamped and highly finished tablet, or the washerwoman her humble bar. From the boiling pans, which are generally