Soap bubble

“ We all know how soap-bubbles are ordinarily formed. A common tobacco-pipe is dipped into a mixture of soap and water, and when it is withdrawn a thin liquid film stretches across the mouth, which we can blow out into a bubble, and then shake off and detach from the tube. I will now perform the experiment of blowing a bubble before you; only, instead of employing a tobacco-pipe, I will use this glass funnel, and for the common soap and water I will substitute a mixture of Castile soap, water, and glycerine. ”

“ A simple puzzle can be made by pasting the picture on cardboard and cutting it up with scissors or a sharp knife.
Soap Bubbles
For blowing bubbles the long clay pipes are best. Before using them, the end of the mouthpiece ought to be covered with sealing-wax for about an inch, or it may tear your lips. Common yellow soap is better than scented soap, and rainwater than ordinary water. A little glycerine added to the soap-suds helps to make the bubbles more lasting. On a still summer day, bubble-blowing out-of-doors is a fascinating and very pretty occupation. ”

“ Even the soap-bubble itself is imperfectly in equi­lib­rium, for the reason that its film, like the protoplasm of amoeba or Aethalium, is an excessively heterogeneous substance. Its surface tensions vary from point to point, and chemical changes and changes of temperature increase and magnify the variation. The whole surface of the bubble is in constant movement as the concentrated portions of the soapy fluid make their way outwards from the deeper layers; it thins and it thickens, its colours change, currents are set up in it, and little bubbles glide over it ”

“ On the Forms of Liquid Films which are Figures of Revolution.— A soap bubble is simply a small quantity of soap-suds spread out so as to expose a large surface to the air. The bubble, in fact, has two surfaces, an outer and an inner Spherical soap-bubble. surface, both exposed to air. It has, therefore, a certain amount of surface-energy depending on the area of these two surfaces. ”

“ The adhesion of the particles in a soap-bubble is another illustration, no less beautiful, as well as more familiar; for the soap, which might be supposed to be the cause of the phenomenon, serves only to prevent the intrusion of dust between the particles, but by no means to intensify their attractive power. ”

“ As you will soon find out if you try, you cannot make with a soap-bubble a great length of any of these curves at one time, but you may get pieces of any of them with no more [Pg 76] apparatus than a few wire rings, a pipe, and a little soap and water. You can even see the whole of one of the loops of the dotted curve of the first figure (A) , which is called a nodoid, not a complete ring, for that is unstable, but a part of such a ring. Take a piece of wire or a match, and fasten one end to a piece of lead, so that it will stand upright in a dish of soap water, and project half an inch or so. ”

“ In pushing a bubble through a ring smaller than itself, by means of a flat film on another ring, it is important that the bubble should not be too large; but a larger bubble can be pushed through than would be expected. It is not so easy to push it up as down because of the heavy drop of liquid, which it is difficult to completely drain away. ”

“ Two or three reliable persons should be chosen for judges to decide the contest. The parents or some older members of the family, at whose house the party is held, usually perform this duty. I should have added, when speaking of the soap mixture, that the common yellow soap intended for laundry use, is much better for this purpose than the finer toilet varieties most commonly used by amateur soap-bubble blowers. ”

“ Bubbles can be set to float upon the vapour without any difficulty. They may be removed in five or ten seconds by means of one of the small light rings with a handle, provided that the ring is wetted with the soap solution and has no film stretched across it. If taken to a light at a safe distance the bubble will immediately burst into a blaze. If a neighbouring light is not close down to the table, but well up above the jar on a stand, it may be near with but little risk. To show the burning vapour, the same wide tube that was used to blow out the candle will answer well. ”

“ A rather rapid motion, or a slight jerk, is all that is required. It is advisable before passing the pipe up through the lower ring, so as to touch the inner bubble, and so drain away the heavy drop, to steady this with the other hand. The superfluous liquid can then be drained from both bubbles simultaneously. Care must be taken after this that the inner bubble is not allowed to come against either wire ring, nor must the pipe be passed through the side where the two bubbles are very close together. ”

“ In knocking bubbles together to show that they do not touch, care must be taken to avoid letting either bubble meet any projection in the other, such as the wire ring, or a heavy drop of liquid. Either will instantly destroy the two bubbles. There is also a limit to the violence which may be used, which experience will soon indicate. ”

“ There is one thing that you can do with soap-bubbles which perhaps you have never thought of. You can make them roll on a table or on the floor by blowing them along. The reason is that the particles of soap and water mixed together hold on to each other, or attract each other, better than the particles of water alone. ”

“ The tank of soapsuds, and the air-pumps to inflate the bubbles, were out of sight beneath, so that when the bubbles began to grow upon the floor of the platform it really seemed like magic to the people of Oz, who knew nothing about even the common soap-bubbles that our children blow with a penny clay pipe and a basin of soap-and-water.
The Wizard had invented another thing. Usually, soap-bubbles are frail and burst easily, lasting only a few moments as they float in the air; but the Wizard added a sort of glue to his soapsuds, which made his bubbles tough ”

“ A slight pressure of air, as every boy blowing soap bubbles can show you, will force a way through a basin full, and the same thing would happen if there should chance to be a backward current of air through these pipes, with this difference, that while the soap bubbles are harmless beauties, these may be filled with the germs of direful diseases. ”

“ If we gather together scrapings of lard, butter, bits of tallow from burned-out candles, scraps of waste fat, or any other sort of grease, and pour a strong solution of lye over the mass, a soft soapy substance is formed. In colonial times, every family made its own supply of soap, utilizing, for that purpose, household scraps often regarded by the housekeeper of to-day as worthless. Grease and fat were boiled with water and hardwood ashes, which are rich in lye, and from the mixture came the soft soap used by our ancestors. ”

“ Unless a soap-ley be rendered caustic, or deprived of its fixed air, it can have no natural attraction for vegetable or animal subtsances, such as oil, tallow, or grease of any kind, so as to convert them into a soap. For the sole purpose, therefore, of extracting the fixed air from the leys, do soapmakers use quicklime. Depriving the mild alkali of its fixed air, renders it caustic, or of a burning, corroding quality, and of that peculiar nature that instantly attach themselves to all greasy substances, and converts them into soap. ”

“ Grease varies so greatly in composition and consistency that it can hardly be classed as a distinctive oil or fat. It is obtained from refuse, bones, hides, etc., and while it contains the same constituents as tallow, the olein content is considerably greater, which causes it to be more liquid in composition. Grease differs in color from an off-white to a dark brown. The better qualities are employed in the manufacture of laundry and chip soap, while the poorer qualities are only fit for the cheapest of soaps used in scrubbing floors and such purposes. ”

“ It is quite possible a variety of other substances may be found associated with the two basic constituents, such as diatomaceous earth, Fuller’s earth, farina, traces of disinfectant, colouring matter, cereal grains, perfume, and even water. But beyond rendering the soap attractive to the eye, pleasant to the nose, or to a certain degree germicidal, these additional materials perform no useful purpose. They are described as fillers, but in more candid language may be set down, for the most part, as sheer adulterants. Few articles lend themselves so readily to adulteration as soap. ”

“ Unsaponifiable Matter.—The usual method adopted is to saponify about 5 grammes of the fat or oil with 50 c.c. of approximately N/2 alcoholic potash solution by boiling under a reflux condenser with frequent agitation for about 1 hour. The solution is then evaporated to dryness in a porcelain basin over a steam or water-bath, and the resultant soap dissolved in about 200 c.c. hot water. When sufficiently cool, the soap solution is transferred to a separating funnel, 50 c.c. of ether added, the whole well shaken, and allowed to rest. ”

“ It is of course understood that the longer the crutching continues the greater quantity of air is incorporated and the increase of volume must be established for a particular composition by sampling, cooling the sample rapidly and seeing if it floats in water. If the beating is continued too long an interval of time, the finished soap is too spongy and useless. ”

“ Effects of Strong Soap on Fabrics. Soap must not be strong enough to injure fabrics or discharge colors, yet sufficiently powerful to render grease and dirt soluble, so that it may be washed away in water. Rosin soap hardens the fibers of wool, and alkalies, if used to excess, shrink woolen fabrics. 54Hard water, or that containing lime or magnesia, more or less decomposes soap, and it floats on the surface as a greasy scum. But if an oily film rises to the top of soft water, it shows that the fat in the soap is not all saponified. ”

“ At its best there is either a considerable excess of free fat which later exhibits itself in producing rancidity or uncombined caustic, which produces an unpleasant effect on the skin when the soap is consumed for washing. ”

“ Through the acid properties of the fats, the oleine, stearine, margarine, etc., which they contain, combine with the alkali to produce the saponified compound.
Hard soap is made with soda; soft soap with potash. The more oleine in the fat, the softer the soap; the more stearine the harder. Rosin is also largely used, sometimes to the extent of one-third the weight of the soap. It increases its hardness, makes it dissolve easier in water and forms a more copious lather.
The Most Economical Soap. Soap may be two-thirds water and still remain solid. Even dry, hard soap contains 20 or 25 per cent. ”

“ Hard water prevents the soap from lathering, and this must be counteracted for laundering. Temporary hardness is removed by boiling. Permanent hardness is not affected by boiling and can be overcome only by the addition of some substance like ammonia, borax, or soda. Only enough of these should be used to allow the soap to do its work, since they may injure fabric and the skin of the worker. ”

“ The acid component of the grease partially neutralizes the base, and a new substance is formed, namely, soap.
With the advance of civilization the labor of soap making passed from the home to the factory, very much as bread making has done in our own day. Different varieties of soaps appeared, of which the hard soap was the most popular, owing to the ease with which it could be transported. Within the last few years liquid soaps have come into favor, especially in schools, railroad stations, and other public places, where a cake of soap would be handled by many persons. ”

“ It is considered the best procedure to commence the pasting or saponification with weak lye.
In order to economise tank space, it is the general practice to store strong caustic lye (60° to 70° Tw., 33° to 37° B.) and to dilute it as it is being added to the soap-pan by the simultaneous addition of water.
Many manufacturers give all their soap a "brine wash" to remove the last traces of glycerine and free the soap from carbonates. This operation takes place prior to "fitting"; sufficient water is added to the boiling soap to "close" it and then brine is run in to "grain" it. ”

“ To do good work with little or no damage to the linen, soft water and good soap are absolutely necessary. In many parts of the United States, the water is permanently hard, and is a perplexing question to laundry workers. The first thing to do is to soften the water. It can not be made soft by boiling, and must be treated with chemicals which must be used before the soap is added. When soap is used in hard water before it has been softened, the soap unites with the minerals in the water, and clings to the linen like a greasy scum. Borax is the best softening agent for hard water. ”

“ The dish is then cautiously heated with a small flame until all the water is driven off and all the soap is dissolved. Care must be exercised not to heat too highly or the oleic acid will decompose. The moment the water is all driven off a clear solution is formed, provided no fillers are present in the soap. The dish is then cooled in a dessicator and reweighed. The loss in weight of acid plus soap is moisture and is calculated on the weight of soap taken. ”