Eustachian tube

“ There is one part of the ear still to be described, namely, the Eustachian tube, so called from Eustachius, the anatomist, who first described it. This tube opens by a wide elliptical aperture into the tympanum behind the membrane; the other end, which gradually grows wider, opens into the cavity of the mouth. By this canal the inspired air enters the tympanum to be changed and renewed, it likewise serves some important purpose in hearing, with the nature of which we are yet unacquainted. ”

“ This is best accomplished by forcing air up the Eustachian tube and through the middle ear by either the Politzer or Valsalva method of inflation. The fluids thus forced out into the external canal can be removed by the use either of warm water and the syringe if large in amount, or by cotton on a cotton-holder if small in quantity: the latter plan is less irritating, and also completely dries the external canal. No local application ought to be made as long as any pain exists. ”

“ If there be no pain and no resistance, the bougie is very gently pushed on until the beginning of its second black band just enters the catheter. Its point will now project 2 centimetres within the Eustachian tube; that is, to about the region of the isthmus. If the bougie has been successfully introduced into the Eustachian tube, the patient generally states that the instrument is felt within the ear itself. No force should be used for fear of making a false passage, and with gentle manipulation it is very rare for actual pain to occur. ”

“ In operating large tubes, that is to say, tubes six or eight inches in diameter, there is an advantage in using compressed, rather than exhausted air, in the construction of the sending and receiving apparatus, especially when the tubes are very long. With an ample supply of compressed air always at hand, the air-cushions can be made shorter and more effective in bringing the carriers quickly to rest.140 With exhausted air the cushions are ineffective, and consequently must be made very long in order to stop the carrier before it strikes the closed end of the tube. ”

“ The most extensive use of small pneumatic tubes in this country has been in our large retail department stores for despatching cash to and from a centrally located cashier’s desk. Seamless brass tubes are usually used, and, since the tubes are short, the air is either compressed or exhausted by means of positive rotary blowers. At the outlying stations the tubes are usually open to the atmosphere, while at the central station simple forms of valves are used for sending and receiving. An outgoing and a return tube are always used, and the air is kept in constant circulation. ”

“ The outer extremity of the two tubes supports the platinum spiral, which is fixed to them very simply by the aid of two small brass needles of conical form, which pinch the wire in the tube and hold it in place. There is nothing easier to do than replace the wire. ”

“ It would be very difficult to bend iron tubes without involving great expense. The thickness of the bent portion of an eight-inch tube is usually three-sixteenths of an inch and never less than one-eighth of an inch. ”

“ The lower end of the tube is firmly supported on rollers that are capable of being moved forwards or backwards by a double rack, connected with a set of wheels and pinions. By an adjustment at the lower extremity of the tube, the speculum is turned to a small inclination, so that the line of collimation may not be coincident with the longitudinal axis of the tube, but may cross the tube diagonally, and meet the eye in the air at about two inches from the edge of the tube, which is the peculiarity of the construction, that supersedes the necessity of applying a second reflector. ”

“ Very small and fine glass tubes, such as are used in experiments to demonstrate capillary attraction, water or other liquid rising in them when they are plunged into it, are made by heating as long a section of tubing as can be handled in the flame—2 in. will be found enough—and, when very hot, giving the ends a sudden vigorous pull apart. The tube pulls out and gets smaller and smaller as it does so, until at last it breaks. But the fine thread of glass so made is really a tube, and not a rod, as might be supposed. ”

“ Where the ground is firm, no other support is needed for the tubes than to tamp the earth solidly about them. In order to economize space in the streets, it is customary to lay the tubes one above the other; and it is very convenient, although not necessary, to separate them by cast-iron saddle brackets. Such an arrangement has to be frequently departed from in order to overcome obstructions in the streets and to get through narrow passages. At all low points in a tube line, traps are provided to catch any moisture that may accumulate. ”

“ Crookes for making air-tight connections between separate pieces of apparatus when a rigid connection would have been unnecessary and inconvenient. By the use of such spiral tubes it is possible to combine comparatively free movement with all the advantages attached to hermetically-sealed joints.
To make a flexible spiral tube, mount a copper cylinder on a screw, so that the cylinder will travel in the direction of its axis when it is rotated. ”

“ The tubes of the Paris system are of wrought iron, in lengths of from fifteen to twenty feet, the joints being made with flanges and bolts. The interior diameter is 2.559 inches with a maximum variation to 2.519 inches. The bends are made with a radius of from six to one hundred and fifty feet. Water frequently gives trouble by accumulating in the tubes. Traps are placed at low points to drain it off. ”

“ Experience shows that, where great exactness of manipulation cannot be obtained, it is necessary to allow only one train in each section of a tube, whether worked by vacuum or pressure. But where there is no intermediate station, and where the tube can be carefully worked, carriers may be allowed to follow one another at short intervals in a tube worked by vacuum, although it is not perfectly safe to do so in one worked by pressure. ”

“ The tubes with one curve are precisely like the inhaling-tubes of the standard olfactometer, except that the part which extends through the screen is longer and is not graduated. It is a mistake to use two-jointed tubes at all, unless both nostrils are to be used, as in compensation-experiments. The extra curve seems to make no difference in the results, but it makes the tubes much harder to clean. The total length of our two-jointed tubes was 18+1⁄2 cm., and that of our one-jointed tubes, 17+1⁄2 cm. 11.3 cm. of every tube used must project beyond the screen. ”

“ It is, however, necessary for one who would succeed in making it, to exercise himself in the art of well bending a tube. After a few attempts, you may finish by producing a pretty-regular spiral. The tube chosen for this instrument should be six or seven feet long, and about one-third of an inch in diameter. You commence by making a bend, nearly at a right angle, about four inches from one of its extremities. ”

“ When so hot that it cannot longer be held in shape, the tube is removed from the flame, and the ends slowly and regularly drawn apart, continuing the rotation of the tube about its axis. By regulating the rate of drawing and the length of tube heated, the desired length and diameter of capillary may be obtained. ”

“ Take a tube which is very regular, and about one-eighth or one-twelfth of an inch diameter in the bore; solder a reservoir at each end, one of them much larger than the other; make a bend near the large reservoir, and then fill the instrument with alcohol to A. Above that, place the first index, which consists of a very small piece of tube closed at one end and cut off square at the other. In the interior of this tube the two ends of a hair are fixed, by means of a little rod of iron, which is pushed into the tube. ”

“ It was his very attitude, I believe, that gave me the strength and the determination to gain the Uxurient after the tube broke free and began lashing wildly back and forth. For a long while I lay gasping on the greendeck; then, when my breath came back, I recoiled the tube, secured the tube-lock, and lifted into space. The soil-solution vat was not as full as I would have wished, but by careful rationing I knew that I could make its contents suffice. Whether I could or not, I wanted no more part of the world I had just left. I never want to see the place again. ”

“ The periscope tube is placed in a slightly larger and very strong steel tube, which passes through the deck of the conning tower and into the latter, and it is made watertight by means of a stuffing-box.
The reason it is necessary to have a fixed outside [136] tube is because the force of the water, when the craft is submerged and is speeding along under power, presses against the tube so hard that if only the inside one were used it would bind; as it is, there is no pressure on the inside tube and it can therefore turn freely at all times. ”

“ In order to reduce the strength of the current a piece of brass tubing, F, is pushed into the space, C, surrounding the core, or if no brass tubing of the required size is on hand, roll a paper tube, cover with 4 or 5 thicknesses of tinfoil and then wrap with more paper, using glue to hold the tinfoil in place and to keep the tube from unwinding. When the tube is pushed all the way in, the current produced will be almost unnoticeable, but when it is withdrawn the current will be so strong that a person cannot let go the handles until the coil is shut off. ”

“ It acts by the reflection of sound-waves on a rubber diaphragm. A small metal disk is cemented to the rubber, and above this is a pointed screw, D. An electric circuit is closed where the points C and D are brought in contact. To locate an obstruction a pistol is fired into the tube as shown, and the resulting wave, traversing the tube at the rate of three hundred and thirty metres a second, strikes the obstruction and is then reflected against the diaphragm, which in its turn reflects it to the obstacle, whence it returns to the diaphragm. ”

“ In this way it is possible to get a tight, smooth tube. Immediately withdraw the core, twisting it slightly in a reverse direction if it tends to stick. Before using the core again, make sure it is free from glue and regrease it. When a sufficient number of tubes have been made and hardened, neatly trim the ends off squarely, and then form an equal number of short tubes, about 2 in. long, by winding a strip of glued paper on a large wire nail until a diameter is reached that will fit snugly into the pipes already made. ”

“ It consists of a tube about an inch in diameter internally, made of flexible spiral wire and India-rubber, and so strong and well protected as to bear the weight of a heavy man without collapsing. The tube is attached to a belt which is firmly buckled to the waist of the operator. The mouthpiece is very ingeniously contrived for holding in the mouth with extreme tenacity and the minimum of inconvenience. There is a glazed eye-protector, which also closes the nostrils. ”

“ Into the syphon tubing a T-tube may be inserted for the purpose of attaching a side tube to be connected with a mercurial manometer, by means of which the exact intra-thoracic pressure may be observed during the operation. The syphon tube should be long enough to provide a fall of one, two, or three feet, as may be necessary. A fall of twelve to eighteen inches is usually enough, as we wish to remove the fluid slowly. We can easily increase the force by lengthening the tube. If the canula should become obstructed, lowering the basin suddenly will probably remove the piece of lymph. ”

“ To excite luminosity in the tube it is not absolutely necessary that the conductor should be closed. For instance, if an ordinary exhausted tube (preferably of large diameter) be surrounded by a spiral of thick copper wire serving as the primary, a feebly luminous spiral may be induced in the tube, roughly shown in Fig. 3. In one of these experiments a curious phenomenon was observed; namely, two intensely luminous circles, each of them close to a turn of the primary spiral, were formed inside of the tube, and I attributed this phenomenon to the existence of nodes on the primary. ”

“ The tube to be heated should be held in the position shown in Fig. 6, supported by the hands on each side. It should be constantly rotated in the flame, that it may be equally heated on all sides. In the figure the hands are represented above the tube, with their backs upwards. A tube can be held equally well from below, the backs of the hands being then directed downwards, and this, I think, is the more frequent habit. It is difficult to say which position of the hands is to be preferred. I lately observed how a tube was held by three skilful amateurs and by a professional glass-blower. ”

“ Inspirations are taken through the tube, and the respired air is discharged through a valve half-way between the belt and the mouth-piece. By drawing a long breath through the tube and removing the mouth-piece a simple sentence can be loudly spoken, care being taken not to inhale without first restoring the mouth-piece. The tube is of sufficient length to communicate by one end with the outer air. A newly-emptied vat, of 1,000 barrels capacity, was selected for the scene of the experiment. ”

“ A tube runs from the left side of this wall to the right wing of the airplane, also from the right side of the wall to the left wing. At the end of each tube there is what we call a 'venturi tube.' This is a kind of suction device operated by the wind. The wind which blows through the left venturi tube sucks the air out of the right-hand side of the mercury tube, and the right venturi tube sucks the air out of the left-hand side of the mercury tube. The stronger the wind, the greater the suction. ”