This proper ventilation of the drum-cavity is needful for perfect function. It is said that the head of the military drum will split if there is no opening in the side; and certainly a stuffed Eustachian tube makes all concussions painful if not damaging to the drum-membrane. Any excess of pressure within interferes with the freedom of the windows, while any lack of air makes pressure on the outside preponderant, forcing in the drumhead and through the chain of hones pressing upon the labyrinth. More than this, if the partial vacuum in the drum cavity is increased through absorption of the unrenewed air by the moist lining, the drumhead becomes stretched until it collapses into contact with the inner wall, or the walls congest and swell to fill the space or else fluid is poured out to occupy the cavity. Generally all of these results are present in varying degree and from this comes the large majority of ear-diseases. So, too, interference with the freedom of the breathing through the nose unfavorably affects the ears. If one holds the nose and blows, air will be forced up the tubes into the drum-cavi ties, and swallowing motions have to be made to relieve the distention. If this swallowing is done while the nose is held closed, strong suc tion is exercised, making partial vacuum in the drum-cavity, and this occurs when cold-taking stuffs up the nose or tonsillar enlargement nar rows the upper throat just behind it. It is not surprising, then, to find that two-thirds of ear patients have middle-ear trouble, only one fourth external-ear affections and in hardly one tenth is the percipient nervous apparatus at fault. This explains why much of the treat ment of ear-diseases must he directed to or through the nose and throat in the effort to restore free ventilation and repair the injury due to the lack of it. The unfavorable influences are often slow and insidious in action; deafness may be advanced in one ear without attracting the notice which any defect of the second ear quickly forces upon the attention; and treatment must be long continued if it is to retrace much of the course by which the affection has passed to its later stages. Discouragemcnts are fre quent, and the conscientious aurist has to tell his patient that only the recent losses can prob ably be recovered, and that ill-health or recur rent cold-takings may offset his best efforts. Yet many of these cases tend to grow steadily worse unless judiciously treated and a gain, however slight, is better than a loss. Mere in flation of air up the Eustachian tube by the Po litzer bag or the catheter can aid the earlier stages; but in chronic conditions intratympanic medication must be used to stimulate the lining of the drum-cavity and retrace the steps by which it has become thickened and stiffened.
Accompanying the defect of hearing for out side sounds there may be greatly increased hear ing of noises within the head. Every one hears a singing in the ear when a shell or other resonator is held against it; and similar results often follow any thickening and stiffening of the conducting apparatus. Tinnitus, as the sub jective sound is called, may be due to many causes, however, and its relief is often difficult. Generally a perception of the sounds of the blood-circulation, it may be caused by changes in the blood itself in ana-mia, by overaction of the heart, by brain-pressure due occasionally to stuffiness of the upper nasal passages, as well as to more local affections. It is usually worse when lying down and in a silent place, since outside noises and occupation of mind and body make it less noticeable; but it is in some cases unceasing and intrusive, seeming to bar out other hearing, and may be almost maddening. In its milder forms it is annoying and excites apprehension of deafness or of brain-disease, with which it is known to be sometimes asso ciated; but its many causes, often wholly trivial, must be remembered and rational measures em ployed for its relief. As stuffing of the Eus tachian tubes or tension of the drumhead and chain of bones are its common causes, much re lief can often be gained by simple hot gargling to free the former, or gentle massage of the drum-structures, as may be well done with the hands.
A curious characteristic of conduction-de fects is the ability to hear better in a noise, often better than normal ears. A person deaf to ordi
nary speech in a quiet place will hear on a train much that is inaudible to persons nearer the speaker. One with nerve-deafness will be duly disturbed by other noises, although perhaps unconscious of defects in a still place.
Only less important than freedom of the Eustachian tube is a healthy free condition of the external canal. This is lined with skin and supplied with glands like the sweat-glands else where, but furnishing the ear-wax or cerumen, which consists of the dead skin-scales and oily material. The purpose of this seems to be to arrest by its stickiness the entrance of dust. small insects, etc., from outside; but it serves a more useful purpose in cleansing the ear. The growth of new skin is most active at the centre of the drumhead and is there rapid enough to spread out over the membrane, moving the older cells before it by a glacier-progress which car ries them beyond the margin and out upon the walls of the canal before they become effete enough to be thrown off. Hence the normal drumhead is self-cleansing and needs no officious aid. The loosening scales of dead skin pass out along the walls of the canal and about its middle become a pasty mixture with the secretion of the cerumen-glands. This clings to the fine hairs of the canal, but is gradually worked out ward by the motions of the jaw-joint, which presses upon the canal, and drying into un noticed scales, it escapes from the exit. Under diseased conditions, including those of the throat and middle-ear, the wax tends to diminish in quantity and grow harder, escaping less readily or collecting in firm plugs. So long as any crack remains for the sound-waves to pass be tween it and the wall, hearing may be unaffected by an almost total filling of the canal; but jarring may force it down upon the drumhead and moisture may swell it into complete closure. Marked and sudden deafness results, often with dizziness, tinnitus or coughing. The plug may dry or crack away from the wall, quickly re lieving the trouble, but only for the time; and it becomes so molded to the irregular curves of the canal as to make it difficult to remove. Most of the sponges and spoons offered in the drug-stores are good only for ramming in the wax more firmly and pressing it down upon the drumhead. They should never be used. The best solvent for ear-wax is hot water, and it should be syringed in with gentle force until the last particle of the plug has been removed. Dropping in of oil or other fluids rarely does much to loosen the collection — they can often increase the distress caused by its presence they certainly cannot remove it, although some hope that they will do so seems present to many that use them. Any violence in digging out the plug or too vigorously working even with the syringe is to be condemned. Underneath it skin flakes have been forming which are often partly incorporated in its mass, partly still fast to the walls —ready like ghangwnailso to tear down into the quick and leave open wounds, very easy of infection. One-seventh of the cases of the aural surgeon require removal of this ear-wax, rather especially of those of his private patients who seek to be too clean. It is easy to do it skil fully and promptly, yet it is often not so re moved. If spoon-like instruments be used at all they should be sharp — they will thus be more efficient, while a mistaken idea of harm lessness will make dull instruments doubly dan gerous. It is true of many a thing besides a firearm that a man °did not know it was loaded.* Seeds, beads and other foreign bodies are sometimes put into the ears. If they are let alone they may remain for many years without doing the least harm ; but forcible removal has often done great or fatal injury. If the ear is directed downward they will often fall out, espe cially with a little rotary rubbing in front of the ear. The syringe will almost invariably bring them away promptly and safely. If they have been rammed in and fixed, it is really gentler to remove them by laying forward the soft parts under ether and operating in the bony canal, even chiseling it wider at need.