Fracture of the Larynx.-Fracture of the larynx is peculiar to the age beyond forty, that being a period of life in which the laryngeal cartilages begin to calcify. The injury in question affects the thyroid cartilage in the great majority of cases, fractures of the cricoid and arytenoids being extremely rare. It is nearly always caused by direct violence (blow while wrestling, attempted strangling).

Fracture of the thyroid cartilage may be either unilateral or bilateral.

The signs consist in ecchymosis, in more or less deformity, and in abnormal mobility. Crepitus is generally absent, but there is always functional disturbance, the severity of which may vary from slight discomfort. to dysphagia and dyspnea. Laryngoscopy generally reveals laceration in the mucous membrane and submucous hematoma.

The treatment must especially take into account the dangers of dyspnea. Intubation should be performed without delay. When there is considerable displacement of fragments, causing endolaryngeal extravasation and consequent edema, tracheotomy should be resorted to. In the treatment of the sequelæ cicatricial stenosis has to be mainly considered. If such a stenosis should supervene, the permanent employment of a tracheal tube will become necessary.

Fracture of the Hyoid Bone.-Fracture of the hyoid bone is produced by the same causes as that of the larynx. It generally takes place at the junction of the corpus with the cornu majus.

The signs are also similar to those of fracture of the larynx, but they are usually much less severe, slight hemorrhage from the mouth, hoarseness, painful

articulation, and deglutition being generally present. Sometimes dyspnea becomes considerable.

The treatment consists in manual reposition, the surgeon's left index-finger reducing the fragment while counterpressure is exerted from the outside by the right index-finger and the thumb. If reposition can not thus be accomplished, an external incision must be made upon the fragment, which can then invariably be reduced by a sharp tenaculum, which secures it during the reducing manipulations.

The patient must be fed by means of an esophageal tube for at least two weeks, and should be directed to keep silent.

APPENDIX.

THE PRACTICAL USE OF THE

RÖNTGEN RAYS.

THE art of skiagraphy can be mastered only after a thorough study of the numerous details of the various apparatus necessary for the production of the Röntgen rays. Its two first and greatest essentials are a high electric current and a Röntgen vacuum tube.

A high current can be obtained in different ways. At present three forms of mechanism are more or less in use: viz., the Ruhmkorff, a simple form of induction coil; the Tesla, or high-tension induction coil, and the static machine. The most efficacious for skiagraphic work is the Ruhmkorff induction coil, which is excited by means of a current derived either from a battery or from a so-called direct current (city supply). A suitable battery, which furnishes a steady current, is the so-called Edison-Lalande cell-battery. For use when traveling, storage batteries may be preferred, the great trouble, however, being that if they become exhausted at a distance from a city, they can not be recharged, while the Edison-Lalande cells can be recharged anywhere.

The direct current, of course, is far superior to any other source, since there is neither charging nor supervising necessary. And, last but not least, the direct

current never embarrasses the operator by proving to be inefficient. Accordingly, whenever possible, con

Fig. 173.-, Rheostat; /, lever; s, adjustable stand; h, handle; w, wheel of motor apparatus; a, anode; c, cathode.

The stronger the coil, the more efficacious the rays, as a rule. While good skiagraphs can be obtained by small apparatus that give a spark of the length of only six inches, in general large coils giving a spark-length of from 14 to 15 inches are to be preferred. An inductor of this power, with a 110-volt direct current, should afford a current strength of from 1 to 2 amperes.

The reliability of a Ruhmkorff coil (Fig. 173) depends upon its thorough construction, and especially upon the proper quality of the wires and the accurate proportion of the windings of the primary and secondary coils. Of special importance is the thorough insulation of the primary from the secondary coil, since any leakage would cause sparking, and would consequently destroy the coil.

Into the interior of the coil a condenser is placed for the purpose of intensifying the result.

If the apparatus is used in connection with a battery, a vibrator must be adjusted, which controls the periodicity of the vibrations. If attached to the direct current, the air-brake wheel should be used, which renders the use of a vibrator unnecessary. The airbrake wheel attachment (Fig. 173, w) permits great rapidity of change in the electric circuit, thus intensifying the electromotive force in the secondary coil. It consists of two tooth-wheels, the projections of which are brought into close contact with two flat brushes, which lead the current in and out, while the dentated wheels are rotated at a high speed by a small motor. This motor runs a pressure-blower at the same time, the air-blast from which is directed to a two-forked tube, through which it is led out again by two flat nozles