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Previous Next The best candle and soap tips online! with which it is in contact,and forms an insoluble carbonate of lime. The pure alkali, or hydrated alkali, remains in solution in the water, and constitutes the caustic lye used in the fabrication of soaps. We may add, that lime used to prepare ljes must always be of good quality, and, if possible, recently burned. It ought to mix easily with water, and should not effervesce with acids. In places where it ia difficult to obtain it readily, it ought to be kept in barrels perfectly closed, and in a dry place, because by being exposed to the air it attracts moisture and carbonic acid. But when lime-kins are near a manufactory of soap, it is better to use lime recently liurtied. When the lime is supposed to contain impurities it would be advisable to submit it to thealkalimetric test, for ttis purpose. Besides titered nitric acid a solution of sal-ammonia is needed, which in one hundred parts, contains about twenty-Jive parts of sal-ammonia. For this test weitjL oft' exactly 2.8 grammes (45.20 grains) of burned lime, place it in the lOOcubie centimetre (3.38 flu. ozs.) trial glass, add at first some water, so that the lime be slacked and reduced to powder; then again 40 cubic centimetres of water (1.35 rtu. oza.), 25 cubic centimetres (0.845 flu. oz.) of the sal-ammonia solution, and finally fill up to the mark with water, until in all 100 cubic centimetres (3.38 flu. ozs ) are obtained. Now place a tightly fitting cork in it, shake repeatedly, and allow the whole to clear oft1, by settling. Then take 10 cubic centimetres (0.338 flu. oz.) of the liquid into a beaker, which contains a ready K1 or 20 cubic centiinetres(0.338 or 0.676 flu. oz.) distilled water, color with tincture of litmus blue, and admit by means of & graduated pipette the normal nitric acid, until the blue color changes into that of a red onion. The cubic centimetres of nitric acid used, multiplied by ten, give the percentage of catstic lime which the tested lime contains. A very good mode for keeping lino for use is to slack it inta a stirt'paste and put it into water-tight vata or barrels where it will keep a long time, while only the upper surface haring absorbed carbonic acid can be remove! before using forcaiisticizing the lye. TECHNICAL TREATISE ON SOAPS AND CANDLES* MATERIALS USED IN THE MANUFACTURE OF SOAPS. 65 "VVATEK. J£au, Fr. Wasser, Ger. Water in the manufacture of soap performs a prominent and indispensable part,and may well be called a raw material. It is particularly important to have it pure, both for the soap and as an ingredient for the lye. There are often dissolved in the water of wells and springs various earthy salts, lime, dolomite, ets. These salts often decompose a portion of the soap, and when used in making or melting they also cause a loss in the causticity of the lye, which in a large factory results in a great pecuniary loss. Thus it is exceedingly important to see that the water used is entirely pure, and if that is not possible, to ascertain the extent and kind of impurities, and to find a suitable remedy to make the water fit for use. To give exact instructions for the analysis of all waters would require much space which is not possible here. Yet, as it is important we will give the test recommended by Fleck, which not only offers the most reliable but furnishes the most ample and accurate results for the techoic, and besides all this, is very feasible. It rests upon the decomposition of the earthy salts which are present in the water, by means of a soap solution of a certain degree. To ascertain the final reaction of the water to be tested, it is only necessary to color the same with an always equal amount of reddish litmus tincture until it becomes light red. As soon as all the earthy Baits are decomposed by the soap, the liquid takes with a new addition of soap solution, a drop at a time, its former bluish color. The soap solution is so normal, that 20 cubic centimetres (0.676 flu. oz.) of it in 100 cubic centimetres (3.38 fln. ozs.) of a saturated solution of gypsum, become decomposed. By this the degree of hardness of a ivater is determined; as also in the case of a, water, of which 100 cubic centimetres (3.38 flu. ozs.) require 20 cubic centimetres (0.676 flu. oz.) soap-solution, and is noted as 20; in other words, the cubic centimetre of soap solution used, expresses the immediate degree of hardness of the water tested. The main requisite for these tests is an entirely neutral 6oa[i; which must contain neither free nor carbonated alkali. The common soapa being for this purpose seldom applicable, Marseilles soap, therefore, as a rub, is used for this purpose. In the absence of this soap, a neutral soap can easily be made, by dissolving a common oil or tallow-soap in distilled water, and settling it with warm culinary salt, and by washing out the grainy soap with a gradually diluted culinary salt solution upon a filter, till the liquid indicates uut a weak alkaline reaction. Finally, the yet moist soap is pressed in linen, in order to remove the still adhering parts of the solution of culinary salt. After drying it somewhat in the air, it is dissolved by warming with about ten times its volume of 70° or 80° alcohol, allowing it to cool off, settle, and then filter Stronger alcohol must not be used, because the solution would congeal. To cause this soap solution to decompose 20 cubic centimetres (0.670 ilu. oz.), put 100 cubic centimetres (3.38 flu. oza.) of a saturated solution of gypsum into a beaker, color the liqjid with some reddened litmus tincture, and add from, a 0.10 cubic centimetre (0.027 flu. dr.) graduated pipette or burette, so Much of the aoap solution as will cause the red color again to become blue. To reach this point with more accuracy, there is next to the first beaker a second beaker, also filled with gyp3iim water, which by means of litmus tincture lias been colored blue. It" on the appearance of the desired blue shade of color, 20 cubic centimetres (0.676 flu. oz.) have been u-*ed of the 6oap solution, it will have tJie correct titer; hat if less have been used, it must in the same proportion be diluted with so much weak alcohol, that 20 cubic centimetres (0676 flu. oz.) are reached. Supposing 12.5 cubij centimetres (0.422 flu, oz.) had been required, then to evci'y 12.5 cubic centimetres of soap solution 7.5 cubic centimetres (0.248 Ilu. oz.) alcohol would be needed; if of the first 11 (0.371 ilu. oz.) was had, so would need 12.5 : 1000 = 7.5 : x = 600 cubic centimetres (20.28 flu. ozs.) alcohol MATERIALS USED IN THE MAJJU.FAOT.UEE OF SOAPS. Previous Next
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