Experiment 33. A long-armed siphon.

FIG. 46THE WATER STOPS WHEN LEVELS ARE THE SAME

You boys who have the Gilbert set on “Hydraulic and Pneumatic Engineering” will know that it is the pressure of the atmosphere which causes the water to run up over the edge of the tumbler in this magical way.

FIG. 47SIPHONING WITH LONG TUBES

Attach a full length of No. 4 tube to each arm of the siphon, as in Fig. 47, and repeat the experiments described above.

Note: When you insert a glass tube into a rubber coupling or rubber stopper, wet the end of the glass tube and the inside of the coupling or stopper, grasp the tube near the end to be inserted, and insert with a twisting motion.

Attach a working handle to one end of a piece of No. 2 tube, heat the tube about one inch from the end in the lamp flame, turn constantly until soft, then remove from the flame, and draw it out about 3 inches. When cool, break off the thin tube, cut off the nozzle to a length of about 2½ inches, smooth the large end, and your nozzle (Fig. 48) is complete.

Arrange the apparatus as in Fig. 49, andsuck air out of the nozzle. Have you made a beautiful fountain?

FIG. 48A NOZZLE

FIG. 49 FIG. 50 FIG. 51 FIG. 52YOU MAKE A NUMBER OF MAGIC FOUNTAINS

YOU MAKE A NUMBER OF MAGIC FOUNTAINS

Make a nozzle 6 inches long out of No. 2 tube. Smooth the ends of the nozzle, and long tubes. Arrange the apparatus as in Fig. 50 and suck air out of the nozzle until the water runs in the siphon. Does the water squirt out of the nozzle in a magical manner?

Arrange the No. 2 apparatus as in Fig. 51, with the nozzle inside the bottle. Now to start the apparatus: Fill the bottle about quarter full of water, insert the tubes in the stopper as shown; insert the stopper into the mouth of the bottle; invert the bottle; then put the short tube in a tumbler full of water and the long tube in an empty pail or basin. Is there a magical fountain inside the bottle?

Repeat this with a taller bottle, if you can find one to fit your two-hole stopper. Do you get a higher fountain?

FIG. 53STARTING A SIPHON

Make another nozzle and attach it to the apparatus used in the last experiment by means of the inverted siphon (Fig. 52). Start the experiment as described above. Do you get two fountains?

FIG. 54SIPHONING SAND

You can start a siphon without sucking the air out of it as follows: Fill the siphon with water, put a finger over each end (1, Fig. 53), place one end in a tumbler full of water and remove the finger under water (2, Fig. 53), then remove the other finger. Does the siphon start?

In this case the water you pour into the siphon drives the air out, and this is the reason you do not need to suck the air out.

Experiment 40. To siphon sand or mud.

Arrange a siphon (Fig. 54), start the water flowing, and then pour sand or mud into the upper tumbler. Is the sand of mud siphoned over into the lower tumbler?

FIG. 55A SQUIRT BOTTLE

Attach a long tube to the outer arm of the siphon and repeat the experiment. Is the sand or mud siphoned more rapidly and more thoroughly?

FIG. 56SQUIRT BOTTLE IN ACTION

Make a nozzle at one end of a piece of No. 2 tubing, make a bend near the nozzle, cut off the other end at such a length that it will reach to within ¼ inch of the bottom of the bottle, smooth this end, allow it to cool, wet the tube and the two-hole stopper, shove it through one hole of the stopper, insert an elbow in the other hole, and your squirt bottle is complete (Fig. 55).

Fill the bottle withwater, and blow through the elbow. Do you get a fine long stream from the nozzle (Fig. 56)?

FIG. 57TUBE FOR TRICK SQUIRT BOTTLE

You can have any amount of fun with a trick squirt bottle. It is exactly the same as the squirt bottle described in Experiment 41 except that it has a hole just below the bend (Fig. 57).

FIG. 58MAKING A SMALL HOLE

To make the hole, make the long bent nozzle as in the last experiment, then heat the tube just below the bend in the blowpipe flame, touch a piece of glass tube to the red-hot glass (1, Fig. 58), and pull it away (2, Fig. 58). Do you find that the hot glass is pulled out into a thin pointed tube? Break off the thin tube close to the large tube, heat in the blowpipe flame until the edges are smooth and at the same level as the sides of the large tube. Flare the edges of the hole, if necessary; it should be about ⅛ inch in diameter.

FIG. 59TRICK SQUIRT BOTTLE

Now fill the bottle with water, and blowhard (Fig. 59). Do you find that one stream of water is driven into your face and another out of the nozzle?

FIG. 60TRICK BOTTLE IN ACTION

Now to have fun with your trick bottle, show it to one friend at a time. Do not ask him to try the bottle, just go where he can see you and squirt a long stream, but unknown to him have your finger over the hole below the bend.

FIG. 61A SIMPLE ENGINEER’S LEVEL(From Aldous’ Physics. Courtesy of The Macmillan Company)

Your friend will just naturally want to have a try at it. So you say “All right, let’s see who can squirt the longest stream.” Tell him that all he has to do is to take a deep breath and blow as hard as he can. He will do so, with laughable results (Fig. 60).

Now together find another friend. Do not ask him to blow, but each of you blow as long a stream as you can, wherehe can see you. He will beg to be allowed to try, and finally you let him, with the same laughable results.

FIG. 62ONE-LEGGED TABLE AND LEVEL

Repeat with other friends.

You can make one form of engineer’s level (Fig. 61) as follows: Take a full length of No. 6 tubing, bend it up 4 inches at each end, smooth the ends, attach it to a small board, rest the board on a one-legged table, and you have a serviceable level (Fig. 62).

Fill the tube with water, shove the pointed end of the leg into the ground and sight along the outside of the upright tubes at the level of the water surfaces. The line along which you sight is exactly horizontal, because the water surfaces are at exactly the same level.

FIG. 63HOMEMADE LEVEL IN USE

An engineer’s level is used to find the difference in level of two or more points (Fig. 63).

To practice using your level, find the difference in level of two points 100 feet apart on a road, sidewalk, or railroad.

To do this, youmust first make what is called a leveling rod. Find a piece of wood about one or two inches square and six or more feet long, mark on it feet and inches, beginning at the bottom end, and your leveling rod is complete.

Now to find the difference in level of two points 100 feet apart, scratch a line or insert a small stake at one point, then pace off 100 feet and mark the second point. Now set up your level between the two points, ask a friend to hold the rod on the ground and upright, at the first point, sight along the water levels at the rod, and ask your friend to move his finger, or a white card, up and down until it is exactly in your line of sight. Now ask your friend to tell you exactly where his finger or card is and record this height. Let us suppose that it is 4 feet 6 inches above the ground. Now leave the level exactly where it is, ask your friend to hold the rod upright at the second point, and again sight along the water levels at the rod. Let us suppose that his finger or card is now exactly 3 feet above the ground.

The difference in level at the two points is 4 feet 6 inches minus 3 feet or 1 foot 6 inches. That is, the second point is 1½ feet above the first point or the grade is 1.5 feet in 100, or 1.5 per cent.

You can now mark a third point 100 feet beyond the second point, set up your level between the second point and third point, place the rod at the second point, then at the third point, and find their difference in level as above. If the third point is 1 foot above the second, the total rise in the 200 feet is 2½ feet; if, however, it is 1 foot below the second, the rise is 1½ minus 1 or ½ foot in the 200 feet.

You can repeat this with as many points as you please.

FIG. 64A SPIRIT LEVEL

The spirit level (Fig. 64) is simply a curved glass tube filled with alcohol except for the bubble and closed at both ends. The curve of the tube is part of a circle.

FIG. 65MAKING A SPIRIT LEVEL

Make a spirit level as follows: Take a piece of No. 4 tube about 7 inches long, heat a space about 3 inches long in the lamp flame, turn constantly, and when soft remove from the flame, hold both ends and allow the center to sink into a slight curve (1, Fig. 65).

Let the tube cool, mark the center of the curve with ink, and make marks 2 inches from the center on each side.

Hold the tube crosswise in the lamp flame, heat at one mark, draw down the tube and close it (2).

In a similar manner draw down the tube at the other mark but do not close it (3).

Let the tube cool and fill it with alcohol to the level shown in 4. To do this easily make the pipette (5), suck alcohol into it within about 1 inch of the top, put your finger over the top, insert the lower end of the pipette to the bottom of 4, and remove your finger.

FIG. 66MOUNTING THE SPIRIT LEVEL

Heat the small part of 4, without heating the alcohol, and close the tube (6). Now attach the level to a smooth board as 2 or 3, Fig. 66, mark the center of the bubble, and your spirit level is ready for use.

Attach a rubber coupling to the large end of one of your No. 4 nozzles, close the other end of the coupling with a glass plug, and your fountain-pen filler is made (Fig. 67).

To make the plug, close one end of a piece of No. 4 tubing, allow it to cool, cut off to a length of 1 inch and smooth the rough edges. Insert the closed end of this plug into the rubber coupling.

Practice using the filler by drawing up and shooting out water.

FIG. 67A FOUNTAIN-PEN FILLER

Take a half length of No. 6 tube and smooth both ends in the lamp flame or blowpipe flame.

Now to make a plunger: Cut an 8½-inch length of No. 2. smooth one end, close the other end and blow a slight bulb. When cold, wet the closed end and insert it into a small wet rubber coupling.

Note: Always grasp a tube near the end when you insert itinto a coupling or stopper, because if you hold it too far back you may break it. Insert it with a twisting motion, after wetting the end and the inside of the coupling or stopper.

FIG. 68A SYRINGE

Wet the inside of the large tube, wet the plunger and rub it on a cake of soap to make it slippery, then try it in the large tube. If the plunger is too large, stretch the coupling lengthwise; if it is too small, crowd the coupling together lengthwise. If the bulb is too large or too small, dry it, heat in the blowpipe flame until it shrinks, and blow another.

When the plunger is made, attach a No. 4 nozzle to the No. 6 tube with a large coupling, arrange as in Fig. 68, and your syringe is made.

Fill the large tube with water and see how long a stream you can make.

FIG. 69ANOTHER SYRINGE

Heat a piece of No. 6 in the blowpipe flame at a length of 7½ inches and draw it out into a nozzle; smooth the other end in the lamp flame. Use the same plunger as in Experiment 48, and your syringe is made (Fig. 69). Try it out with water.

Heat a piece of No. 6 tube in the blowpipe flame at a length of 7½ inches, draw it out, and close the end, then smooth the other end.

Now to make a plunger: Heat a piece of No. 2 tube 8½ inches from one end in the lamp flame, draw it out into a nozzle, and break it off, leaving a small hole at the end of the nozzle. Smooth the other end in the lamp flame, flare it out slightly, allow it to cool, dip it into water and insert it into a small wet coupling.

FIG. 70A THIRD SYRINGE

Now fill the large tube with water and insert the coupling plunger (Fig. 70). Do you get a fine long stream?

Use the No. 6 tube and the No. 2 plunger from Experiment 48, arrange as in Fig. 71, blow across the top, and move the plunger up and down. Do you get a most diabolical sound?

FIG. 71THE DIABLO WHISTLE

The sound is produced by the vibration of the air column between the top of the tube and the top of the plunger. Do you find that the pitch of the note is higher the shorter the air column?

Start with the air column long and blow the note, shorten it a little and blow the next note, continue, and tryto blow the eight notes of an octave.

FIG. 72JOINING TWO TUBES

Try to play a tune.

Try to make the most weird sound you can.

Take a piece of No. 2 tube about 7 inches long, close one end, smooth the other, and when cool cut the tube at the middle.

FIG. 73WORKING THE JOINT

Now join these two pieces as follows: Hold the ends opposite each other near the top of the lamp flame (Fig. 72), rotate constantly, and when nearly red hot bring the ends accurately together in the flame, press together slightly, draw out slightly, and remove from the flame.

The ends are now stuck together, but the glass is in a slight lump around the joint and if allowed to cool will crack very easily. It is necessary to work the glass back and forth to get rid of the lumpand to make the glass uniform on both sides of the joint. Do this as follows: Heat one third of the joint in the blowpipe flame (Fig. 73), and when red hot blow a slight bulge. Now turn the joint one third, heat the next third red hot and blow a slight bulge. Repeat with the remaining third.

FIG. 74JOINING TUBES OF DIFFERENT SIZES

Now heat the first third again until it is red hot and shrinks, then blow a slight bulge again. Repeat this with the other two thirds.

Repeat this whole operation a third time and blow just enough to leave the joint the same size as the remainder of the tube or a little larger.

FIG. 75MAKING A LARGE HOLE

This heating and blowing has worked the joint back and forth until the glass is fairly uniform. It makes a strong joint.

Cut off the closed end and smooth the edge.

Repeat with a piece of No. 4 tube.

FIG. 76MAKING A TEE

Take a piece of No. 4 tubing about 3 inches long and close one end.

FIG. 77THREE-ARMED SIPHON

Take a piece of No. 6 tubing, attach a handle to one end, heat the No. 6 tube in the blowpipe flame about 1 inch from this end and draw it down to smaller size.

Break the small part at a point where it is about the size of the No. 4 tube. If the hole is too large, heat the edge until it is a little too small and flare it out with the flaring tool. If the hole is too small, heat the edge and flare it out.

Now heat the ends of both tubes (Fig. 74), and join them as described in the last experiment.

Repeat the operation of heating and blowing at least three times.

Join a No. 4 and a No. 2 tube in the same way.

Take a piece of No. 4 tube about 6 inches long, close one end, smooth the other, and allow it to cool.

FIG. 78A REPEATING AIR GUN

Now to make a large hole in the side of this tube, proceed as follows: Heat in the blowpipe flame the point at which you wish to make the hole, and blow a slight bulge (1, Fig. 75). Then heat the top of this bulge until it is red hot over an area about equal to the size of the hole you wish to make, and blow hard to make a thin bubble (2, Fig. 75). Break away the thin glass of the bubble, smooth the edges, and the hole is made. The edge of this hole will project beyond the side of the tube (3, Fig. 75). If you wish to make the edge even with the side of the tube, heat it in the blowpipe flame until it shrinks back level with the tube.

FIG. 79FOUR-WAY JUNCTION

Take a piece of No. 4 tube about 6 inches long, close one end, smooth the other, and allow it to cool. Take another piece 3 inches long, close one end, and allow it to cool.

Now make a hole in the side of the first tube at a point 3 inches from the closed end. Do this as described in the last experiment but leave the hole projecting beyond the side of the tube (1, Fig. 76).

FIG. 80MAKING A Y

Now heat the edge of the hole and the end of the short piece in the lamp flame, and make a joint (2, Fig. 76) exactly as described in Experiment 53. Be particular to heat and blow all around the joint at least three times to make the glass uniform, and on the last blowing leave the joint a little larger than the tube. Cut off the closed ends, make the arms equal in length, smooth the ends, and your tee is made (3, Fig. 76).

Your first attempt may not be beautiful, but if you will repeat the heating and gentle blowing often enough, the joint will be strong, which is the main point.

Repeat until you can make a tee easily.

Make a tee with No. 2 tubing.

Your flame is hardly large enough to make a tee with No. 6 tubing.

Make a three-armed siphon as shown in Fig. 77. Put two arms in tumblers filled with water, suck air out of the third arm until the water runs, and then put it in an empty tumbler.

Stand the three tumblers on the table. Does the water run until the levels are the same?

Put one tumbler on a book. Does the water run into the other two tumblers until the levels are the same?

Return the one tumbler to the table and put the other two onthe book. Does the water run from both tumblers to the lower tumbler until the levels are again the same?

FIG. 81BALANCING COLUMNS

Take a full length of No. 4 tubing, put a branch about 3 inches long at a point about 2 inches from one end; leave the end of the branch closed (Fig. 78). Now load the branch with shot or coarse dry sand, and your repeating air gun is ready for use.

Tilt the branch slightly above the horizontal and blow intermittently. Does your gun reload after each blow, until the ammunition is used up?

Make a tee as in Experiment 56, but do not cut off the closed ends. Now attach a fourth arm, as in Fig. 79, and heat and blow gently as before to work the glass into uniform condition. Cut off the closed arms at equal lengths, smooth the ends, and your four-way junction is made.

Experiment 60. A four-arm siphon.

Make a four-arm siphon, repeat the experiments described in Experiment 57, and make others of your own.

Make a tee as in Experiment 56, then make a bend about ½ inch from the stem on each side (Fig. 80), and your Y is complete.

Arrange the apparatus as in Fig. 81, put the arms together in a glass of water, suck a little air out of the top coupling and close it with a glass plug. Do you find that the water rises to the same level in each?

Place the arms in separate tumblers filled with water to the same level and repeat. Does the water rise to the same level?

FIG. 82THE WATER LEVELS ARE THE SAME

Add an extra length to one arm and repeat. Are the levels different but are they equal distances above the water in their respective tumblers?

Place the tumblers on the table, make one tube slanting, and repeat the experiment (Fig. 82). Are the levels again the same?

When you suck air out of the tee, you decrease the air pressurein the two tubes, and the atmospheric pressure on the water in the tumblers lifts the water into the tubes.

Put a large handful of salt into a tumbler partly filled with water and stir until the salt is dissolved. Now pour fresh water into another tumbler until it is at the same height as the salt water. Make the arms of equal length, put one arm in the salt water and the other in the fresh water, then suck a little air out of the top coupling and close it with a plug. Do you find that the column of salt water is shorter than the column of fresh water (1, Fig. 83)? It is shorter because salt water is heavier than fresh water.

FIG. 83UNEQUAL COLUMNS

If you have gasoline or kerosene convenient fill one tumbler half full of either, and the other tumbler half full of water, then repeat the experiment. Do you find that the column of gasolineor kerosene is longer than the column of water (2, Fig. 83)? It is longer because gasoline and kerosene are lighter than water.

Find a piece of thin iron or copper wire about 4 inches long, heat the end of a piece of No. 2 tubing until it is nearly closed, insert the iron or copper wire into the small hole, and heat the glass around the wire until it shrinks and grips the wire firmly (Fig. 84). The glass then serves as a handle for the wire.

FIG. 84WIRE FUSED INTO GLASS

It is difficult to make a secure joint between iron or copper wire and glass because they both expand and contract more than glass when heated and cooled. It is easy to make a secure joint between platinum wire and glass because platinum and glass expand and contract at practically the same rate when heated and cooled. Platinum, however, is too expensive to be used for ordinary experiments.

The common glass cutter is a small very hard steel wheel mounted on a handle (Fig. 85). Practice with one on a pane of glass: place a ruler on the glass, draw the wheel along the ruler (Fig. 86) with sufficient pressure to scratch the glass, place the under side of the scratch exactly over the edge of the table, and press down on both sides.

FIG. 85A GLASS CUTTER

Experiment 66. To bore a hole in glass.

FIG. 86CUTTING A PANE OF GLASS

Place a piece of window glass flat on the table, pour a little kerosene on the spot to be bored, clasp the file near the end, press the end down hard on the spot and turn it back and forth with a gouging motion (Fig. 87). You twist the file just as you would twist an awl to force it into hard wood.

You will soon penetrate the surface; use plenty of kerosene and continue the boring until you are nearly through; then turn the plate over and start a hole on the other side to meet the one you have made.

FIG. 87BORING A HOLE IN GLASS

Do not rush things; it will take you ten or fifteen minutes to bore through ordinary window glass.

Bore a hole in a bottle in the same way, except that the boring is all from the outside.

If the end of the file becomes dull, break off a small piece, with a pair of pliers, to expose a fresh surface.

Experiment 67. To cut a bottle in two.

FIG. 88BOTTLE READY TO BE CUT IN TWO

Wind a strip of blotting-paper or wrapping paper 2 inches wide around the bottle at one side of the line along which you wish to cut. Make three or more thicknesses and then tie the paper with cord within ½ inch of the edge to be cut. Wrap another similar piece on the opposite side of the place to be cut and ³⁄₁₆ inch from the first piece (Fig. 88).

FIG. 89HEATING THE BOTTLE

Now stand the bottle in a pail of water until the paper is thoroughly wet (about five minutes), take it out, rotate it in a horizontal position and direct the blowpipe flame against the glass between the papers (Fig. 89).

Continue this for four or five minutes, then if the bottle has not dropped apart, plunge it vertically into the pail of water.

The bottle will break into two parts along the line between the two papers (Fig. 90). If it does not do so, repeatthe operation until it does. Smooth the rough edges outside and inside with the file. You cannot do this with the flame because the glass is too brittle.

FIG. 90THE BOTTLE CUT IN TWO

Rough edges of glass can be ground smooth by means of emery paper. For example, to smooth the edges of the glass bottle you have just cut in two, use the file for the rough work, then lay a piece of emery paper on a plate of glass, emery side up, pour a little kerosene on it and rub the rough surface on the emery with a rotary motion (Fig. 91). Finish with fine emery paper, and smooth the edges inside and out with the fine paper.

FIG. 91SMOOTHING THE EDGES

There are two important points to remember in cementing glass: first, to get the glass clean, and second, to press the surfaces together after applying the cement, to squeeze out as much of the cement as possible,and to keep them pressed together until the cement is hard. To clean the glass wash it thoroughly with soap and water, rinse, and dry with a clean cloth.

FIG. 92CEMENTING GLASS

There are many excellent glass cements on the market. Some of these are solid and are used only on hot glass; others are liquid and are used on cold or hot glass.

Cement two strips of glass together (Fig. 92) with sealing wax or solid shellac or some other solid cement as follows: Clean the glass thoroughly, place in the oven or on the stove, heat gradually until the glass just melts the cement, rub the cement over both surfaces, bring them together when the cement is fluid, press them together to squeeze out as much cement as possible, and keep them pressed together until the cement is hard.

Cement a strip of wood to a strip of glass in the same way.

Cement a strip of wood to a strip of glass with liquid glue, both wood and glass being cold. Keep them pressed together until the glue is dry, perhaps a day or two.

Boys, you can perform many magic experiments with apparatus made out of the glass tubes, rubber stoppers, and rubber unions supplied with “Experimental Glass Blowing.” We outline a number in the following pages. You can invent many more for yourselves.

Light your alcohol lamp, blow it out, and bring a lighted matchdown toward the wick from above (Fig. 93). Does the lamp light in a most magical mannerbefore the match touches the wick?

FIG. 93MAGIC

Repeat this with a kerosene lamp and with a candle. Do they light in the same magical manner?

When the lamp is lighted, the alcohol or kerosene turns to a gas, and it is the gas which burns; when the candle is lighted, the wax turns to an oil, the oil turns to a gas, and it is the gas which burns.

The gas rises from the wick for a short time after the flame is blown out, and it is this gas which lights when you bring the match down toward the wick.

FIG. 94THE CANDLES GO OUT AND THE WATER RISES

Drop melted candle wax on a tin can cover and attach the bottoms of two candles to the cover (Fig. 94); use one candle about4 inches long and another about 3 inches, stand them upright in a pan of water, light them, and invert a wide-mouthed bottle over them. Does some air escape at first due to expansion, do both candles go out, the taller one first, and does the water rise until the bottle is about one-fifth full?

FIG. 95THE CORK RISES

Cut a piece of candle ½ inch long, float it on a flat cork or can cover in the pan of water, light it, and invert a fresh empty bottle over it (Fig. 95). Is the result similar?

The water rises in the bottle because ⅕ of the air is used up by the burning candle. Air is ⅕ oxygen and ⅘ nitrogen. The oxygen unites with the burning gas of the candle and produces water vapor (H2O) and carbon dioxide (CO2); the nitrogen takes no part in the burning.

FIG. 96WATER FROM FLAME

The water vapor (H2O) condenses to water on cooling and takes up very little space. The carbon dioxide remains a gas and occupies space, but this is offset by the volume of the air which escaped at first. The result is that the volume of gas at the end is about ⅕ less, and the atmospheric pressure on the water in the pan lifts water into the bottle.

The candle goes out because it must have oxygen to burn and the oxygen is used up.

It is certainly magic to produce water from fire, but you can do it easily as follows:Hold a clean, dry, cold tumbler over your alcohol lamp flame (Fig. 96). Does water deposit in the form of mist on the inside of the tumbler?

FIG. 97ATMOSPHERIC PRESSURE

Repeat with fresh tumblers with the flame of a kerosene lamp and of a candle. Are the results similar?

Direct the blowpipe flame into the end of a piece of No. 2 or 4 tubing. Does water deposit in drops inside the tube about 1 inch above the end?

One of the chief constituents of alcohol, kerosene, and candle wax is hydrogen (H), and when this burns in the oxygen (O) of the air, it produces water (H2O). It is this water which condenses on the cold glass.

Arrange a No. 6 tube as in 1, Fig. 97, and suck air out at the top. Does the water run uphill into your mouth?

Hold your finger over the top and lift the tube out of the pail (2). Does the water remain in the tube? Fill a bottle with water to overflowing, insert a No. 2 tube into your one-hole stopper, insert the stopper into the mouth of the bottle (3) without admitting air below the stopper, and try to suck water out of the bottle. Do you find that you cannot do so?

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