instances not sufficiently stiff to resist their pressure. The pilot, shown in Fig. 171, inasmuch as it renders the end of the tube stiff and wedge-shaped, facilitates its introduction. The Indiarubber tubes may be worn with the greatest comfort, and for prolonged periods. I have now a patient who has worn them for upward of three years. When lined with canvas, as suggested by Mr. Baker, the tube will last in very good condition for nearly twelve months. If a silver tube be worn it should be examined on each removal, any blackening of the end, and, of course, the presence of blood, being an indication that ulceration is in progress. The tube should only be worn as long as respiration through the glottis is impeded. To determine when the tube may be dispensed with, it is only necessary to close the wound with the finger, and thus test the breathing. As a rule, it is better to remove the tube at first only during the day, or for a few hours at a time, or where a fenestrated cannula is used, the external opening may be stopped for certain periods with a plug, to gradually accustom the patient to breathe through the glottis. When the tube has been worn for any length of time some difficulty is often experienced in leaving it off. This may depend chiefly on: 1, the formation of granulations in the trachea above the opening for the tube; 2, adhesions of the vocal cords to one another; and 3, paralysis, complete or partial, of the intrinsic muscles of the larynx. Thus, where granulations are the cause of the obstruction, they should be touched at intervals with nitrate of silver. Where there is adhesion of the vocal cords the glottis may either be dilated by Schroetter's tubes or the adhesions broken down by probes passed up through the wound or down through the mouth. The power of the muscles may be restored by galvanism, one pole being placed in the larynx and the other over the situation of the recurrent laryngeal nerve. In children the condition improves as they grow older and the larynx becomes more developed.

LARYNGOTOMY.-Feel for the cricoid cartilage, and if the case is urgent, and the patient evidently in extremis, plunge a penknife through the skin and subjacent crico-thyroid membrane transversely, immediately above the cricoid cartilage, and hold the wound open by a hair-pin, piece of wire from a champagne bottle, etc. When the operation can be done deliberately, make an incision exactly in the middle line of the neck, from a little above the lower border of the thyroid cartilage to a little below the upper border of the cricoid cartilage, and the crico-thyroid membrane having been thus exposed, incise it transversely, entering the knife immediately above the cricoid cartilage, so as to be as far as possible from the vocal cords, and to avoid wound

ing the little crico-thyroid artery, which anastomoses with its fellow usually across the upper part of the space. This artery, though commonly so insignificant in size that any hemorrhage from it could be readily controlled by the tube, is sometimes of considerable dimensions, and, if then wounded, would require tying. The laryngotomy tube should be somewhat compressed from above downward, so as better to correspond with the shape of the crico-thyroid space. Some surgeons recommend that the incision through the crico-thyroid membrane should be vertical, as the anterior jugular vein and the crico-thyroid muscles have been injured in making the transverse, and an aerial fistula has at times remained after the latter has been employed. Further, the vertical incision has this advantage, that it can be prolonged downward through the cricoid cartilage if more room is required. LARYNGO-TRACHEOTOMY Consists in prolonging the incision in the trachea through the cricoid cartilage. It is sometimes done when there is not room between the cricoid cartilage and the isthmus for the performance of tracheotomy; also for the purpose of removing a growth from the larynx. Although no harm. may follow the division of the cricoid, it should be avoided, if possible, as the integrity of the larynx is interfered with, and serious impairment of the vocal apparatus has been the result.

Comparison of the Operations of Tracheotomy and Laryngotomy.-Laryngotomy is a much easier operation and can be done with greater rapidity than tracheotomy. For this reason, it is par excellence the one to be undertaken on an emergency, as, for instance, threatened suffocation from the impaction of a portion of food at the entrance of the larynx. În children, tracheotomy, or, in the case of an emergency, laryngo-tracheotomy, should always be undertaken, as the crico-thyroid space in them is too small to admit a tube. In adults, when either laryngotomy or tracheotomy can be performed deliberately, the opinions of surgeons are somewhat at variance as to which operation ought to be undertaken for the varying conditions calling for an opening into the air passages below the glottis. For my own part, I always do tracheotomy, except in cases of emergency, as this operation does not interfere with the integrity of the larynx; whereas after laryngotomy the voice has at times been lost or impaired, owing to contraction of the crico-thyroid membrane, or inflammation of the crico-thyroid joint or cricoarytenoid joint. This opinion, however, is not held by all. Thus, according to Mr. Erichsen, laryngotomy should be performed in 1. Acute cedematous laryngitis. 2. Membranous laryngitis in adults. 3. Chronic syphilitic and ulcerative laryngitis. 4. Tumors and foreign bodies obstructing the larynx.

5. Scalds and injuries of the larynx by acids. 6. Accidents during operations about the head and face in which blood accumulates in the larynx. 7. Laryngeal spasm and paralysis from compression of the recurrent nerve. Tracheotomy, on the other hand, should be done for: 1. Membranous laryngitis in children; 2. Foreign bodies in the trachea or bronchi; 3. Impaction of foreign substances in the pharynx; 4. Necrosis of the cartilages with obstructive thickening of the tissues; and 5. As a preliminary to certain operations attended with hemorrhage about the face or mouth.

THYROTOMY, or laying open the larynx from the front by dividing the thyroid cartilage in the middle line, may be required for the removal of a tumor or a foreign body impacted in the larynx after a thorough and careful attempt has been made to extract it by the natural passages (intra-laryngeal method). Make an incision accurately in the middle line of the neck from the hyoid bone to the cricoid cartilage, and, having exposed the thyroid cartilage, and stopped all bleeding, divide it along the angle formed by the junction of the alæ, taking care to do so in the middle line so as not to injure the vocal cords. Separate the alæ, and remove the growth, etc., and bring the alæ accurately together again, and unite them by silver wire or kangaroo-tailtendon sutures, which should not, however, be passed through the whole thickness of the cartilage. When the removal of the growth is likely to be attended by hemorrhage, tracheotomy had better first be performed and the trachea plugged by Hahn's cannula.

SUBHYOID PHARYNGOTOMY consists in opening the pharynx through the thyro-hyoid membrane for the purpose of removing a tumor or impacted foreign body at the entrance, or in the upper part of the larynx. It is so rarely required that the steps of the operation are not given in detail here.

EXTIRPATION OF THE LARYNX.-Partial or complete removal of the cartilages of the larynx may be required for malignant disease when the growth is confined to that organ and the glands in the neck are not involved. First perform tracheotomy, and plug the trachea with Hahn's tampon cannula, and continue the administration of the anesthetic through it. Next make an incision in the middle line of the neck from the hyoid bone to the tracheotomy wound; free the upper part of the trachea and the larynx from their attachments by dissecting close to these structures, securing all bleeding vessels as they are divided. Divide the trachea above the cannula and detach the larynx from the remaining connections, working from below upward. Where part of the larynx can be saved, the risks of the operation will be

greatly lessened. Lightly plug the wound with iodoform gauze, leaving the cannula in situ. The patient must be fed at first through a soft tube passed down the oesophagus, and by nutrient enemata. On the healing of the wound an artificial larynx should be fitted to the parts, by the help of which the patient will be able to speak moderately distinctly.

DISEASES OF THE PAROTID GLAND.

PAROTITIS, or MUMPS, is an acute infectious disease attended by sharp febrile disturbance, and by a local inflammation of the parotid gland. There is generally much pain and swelling, but neither redness nor tendency to suppuration. On the subsidence of the inflammation in the one gland, the opposite, if not already affected, generally becomes inflamed, or more rarely the testicle, ovary or mamma is attacked-a condition spoken of as metastasis. Confinement to the house, a gentle laxative, and a belladonna or opiate liniment to soothe the pain are all that is usually required.

In

PAROTID TUMORS may begin in the parotid gland itself, or, as is perhaps more often the case, in one of the lymphatic glands situated over it. They have a great tendency to displace or destroy the parotid, and to extend deeply among the important structures behind the ramus of the jaw, where they may surround the carotid arteries, or even encroach upon the pharynx. structure they may be fibrous, myxomatous, cartilaginous, sarcomatous or carcinomatous. The tumor, however, most common in the parotid region consists of cartilage intermixed with fibrous tissue and atrophied glandular elements, and often with mucous tissue. The cartilage which so frequently exists in parotid tumors is believed to be derived from the elements of the rudimentary foetal structure concerned in the development of the lower jaw, and known as Meckel's cartilage. Cysts are very rare, but cystic degeneration of the solid tumors is not infrequent.

Symptoms and Diagnosis.-The differential diagnosis of the various parotic tumors cannot be here attempted. Nor is it of consequence, as it is often impossible before removal to determine their exact nature. The practical points for the surgeon to consider are: Is the growth innocent or malignant, and can it be safely removed? Innocent tumors grow slowly, and are at first freely movable, smooth or slightly lobulated, circumscribed, hard and firm or semi-elastic; but as they increase in size they may become soft or fluctuating in places, either from mucoid softening or cystic degeneration. The skin over them, though stretched and thinned, is non-adherent, and the glands are not affected.

Malignant tumors, on the other hand, grow rapidly, are ill-defined in outline, generally soft or semi-fluctuating, and become firmly fixed to the surrounding parts; the skin is adherent, purplish-red, brawny, infiltrated with the growth, and later ulcerated; and the lymphatic glands are enlarged. An innocent tumor, however, after having grown slowly for many years, may suddenly take on a rapid growth and malignant characters.

Treatment. When the tumor appears innocent, of moderate size and freely movable, indicating that its attachments are not deep, there can be no question about its excision. But when of very large size, especially if firmly fixed to surrounding parts, or if malignant, unless quite small and the skin and glands are not to any extent involved, it should be leftal one. The Operation. -Make a free longitudinal incision through the skin and fascia to thoroughly expose the tumor; it will then often readily slide out of its capsule; if not, draw it forward with vulsellum forceps, and separate its deeper attachments with the handie of the scalpel and occasional touches of the knife, the edge of which should be turned toward the tumor to avoid the branches of the facial nerve and other important structures. The proximity of the carotids should not be forgotten.

DISEASES OF THE THYROID GLAND.

BRONCHOCELE, Goitre of DERBYSHIRE NECK is an enlargement of the thyroid gland. It may be due, as is commonly the case, to the simple hypertrophy of the normal tissues of the organ (ordinary goitre), and may then involve the whole gland or one of the lateral lobes, or only the isthmus. In other instances the hypertrophy may fall chiefly on the fibrous tissue constituting the septa of the gland (fibrous goitre). Or along with some amount of simple hypertrophy, or of increase of fibrous tissue, one or more of the normal alveolar spaces may become enlarged, forming single or multiple cysts (cystic goitre). Such cysts contain when single a serous fluid, or when multiple a colloid or a dark grumous material sometimes mixed with altered blood; while occasionally proliferating growths project into their interior from their walls. In other instances, again, but more rarely, the hypertrophy is associated with a great increase in the vessels, and a forcible and expansile pulsation is given to the gland (pulsating goitre). But the tissues besides hypertrophy may undergo secondary changes. Thus calcification may occur, and the enlarged gland become in places of stony hardness (calcified goitre), or the fluid normally contained in the alveolar cavities may assume a colloid character. Lastly, the enlargement of the thyroid may be due to malignant disease (malignant goitre).