The action of the sympathetic nerve just described can be clearly shown in a transparent tissue, such as is found in the ear of a white rabbit. Section of the sympathetic supplying the ear causes a deep blush to suffuse the whole organ, showing an increase of blood supply from an enlargement of the calibre of the blood-vessels. On the other hand, irritation of the cut end of the sympathetic by an electric discharge immediately produces an unnatural pallor in the pinna of the ear. Now, a considerable portion of the blood supply of the membrane of the drum is derived from an artery that leaves the internal carotid and proceeds by a very short course to its destination, being thus closely connected with a large arterial trunk; this small artery possesses very favorable circumstances for a speedy augmentation of its blood supply. Now, the sympathetic supplying the carotid plexus comes largely from the otic ganglion, which ganglion controls the circulation of this part. On the other hand, the inferior dental nerve supplying the teeth and gums also communicates with this ganglion. We thus arrive at a direct channel of nerve communication through the otic ganglion, between the source of irritation, the tooth, and the vascular supply of the drumhead. Therefore, any irritation of the nerve in the vicinity of the tooth passes upwards to the otic ganglion, from which it is reflected to the nerves governing the blood supply of the drum, the vessels of which become largely distended, and if the irritation be sufficiently prolonged, an effusion takes place into the tissues of the drum, and finally, the formation of pus results. This disturbance of the vessels soon extends deeper and pus distends the internal ear, causing perhaps rupture of the drum, or terminating in convulsions and death. It will thus be clear that earache, under whatever circumstances it occurs, whether resulting from tooth diseases or any other cause is never a trivial accident to be treated with a boiled onion or warm oil. The correct treatment may be roughly summarised under two heads:1st. Removal of the cause, as by lancing a swollen gum or removing a decaying tooth. 2nd. By the treatment of the effects, which will vary according to the stage at which they have arrived. Thus, if there is only a hyperæmia, apply a leech inside the pinna of the ear, and give small doses of tincture of aconite frequently, to diminish the heart's action, following this up with syringing the ear with warm water. If the disease has gone on to the formation of matter, we must follow the ordinary rule and give exit to it either by puncturing the drum or opening the mastoid cells.

33, St. James Street, London, W.C.

Mechanical Dentistry.

CLASPS AS FASTENINGS FOR ARTIFICIAL DENTURES. By J. W. CLOWES, D.D.S., New York.

THAN these, no items of professional practice have received more of my attention, and I am convinced, by long experience, of their entire reliability. Their sphere of usefulness, confined as they are to partial sets, is limited. Having a reputation as harm-doers in the past, I must needs be cautious in disclosing their excellence. To this end, the thing to be fastened as well as its fastening must be discussed; for a well-fitting plate and clasp must ever be united to attain success. In my practice, narrow but doubled gold plates are used, composed of what may be called the base and stiffener. Í employ two castings and two counters. The base and stiffener are separately struck up and swaged. They are placed together and swaged again. Joined by a fine solder, they are again swaged, and all this between the same casting and its counter. Annealing should always precede swaging. Having advanced thus far by means explained, I now bring forth my reserved casting and make the impress of the unchanged form upon my plate. My attention is next given to the fitting of the clasps. Several important points are to be considered in this connection,—a good hold is to be gained, damage to the natural teeth avoided, and ease secured in applying, wearing and removing the plate. These requisites are absent while the natural teeth retain their original form.

If the clasps surrounding the teeth merely touch the centre of protuberance the hold is slight and unstable, while the liability to injure is greatly increased by retention of extraneous deposits. Hence is shown the necessity for plain surfaces in the application of clasps. Approximal sides of all teeth which I intend to clasp are carefully and skilfully flattened with the file. Toughness and elasticity are essential qualities of a good clasp, and they are obtained by the alloyment, in due proportion, of gold with platinum. When about to fit clasps I take the measure of the parts to be clasped with a piece of sheet lead. This pattern enables me to approximate pretty nearly to the length and width which I desire, and prevents waste of material. The gold, having been cut according to its pattern, is rounded and

CLASPS AS FASTENINGS FOR ARTIFICIAL DENTURES. 413 smoothed on its edges, and when annealed, is ready to be bent and shaped for use.

My clasp fitting is done entirely with pliers upon the teeth as they stand in the mouth, and my reliance is never upon any form of them which may be gained by impressions in plaster

or wax.

The part of a clasp first to be fitted should turn the posterior buccal corner of the tooth, passing along its approximal and flattened side to wind around its lingual swell, thence straight across its anterior face to a point just short of ocular perception. The turn at the place of beginning should be long enough to embrace the corner and enable the patient, by catching it with his finger nail, to remove the plate from the mouth. Clasps should never be allowed to irritate and inflame the gums.

Having adjusted the plate to the gums and the clasp to the teeth, our next effort must be to connect them. If we succeed in this without in any way impairing the excellence of the work already accomplished, we may indeed rejoice. The plate fits and the clasps fit, but the momentous question is will they fit when united? I have seen the day when to be able, confidently, to say yes to this would have been manna to my soul! Groping in darkness, attended by defeat, is hard upon the constitution, and, looking back to my early days of professional trial, I confess to having often endured the rack from this very inability to make two things fit when together just as well as when apart.

With the plate and clasp in position we proceed to take a try-plate impression. This may be obtained in plaster or wax. I prefer wax. For this purpose, if I have taken the original impression in wax, it is preserved in the pan until needed. This impression should be softened with warm water, retaining a sufficiency thereof in the clasp-teeth walls to render them softer than the rest. Now insert the plastic wax; with the thumb and two fingers of each hand apply it; steady, now; exert no undue pressure on any one part, but firmly and evenly do the work. Withdraw it carefully and without rocking. You have it now,-a try-plate impression, the very key, if you know how to use it, to ultimate success.

With the impression in your hand what next? Remov the plate and clasps from the mouth and restore them to their impressions in the wax-but, softly, the clasps first and after them the plate. But-softly again-you must not attempt to replace the clasps in the wax until you have expanded them with the pliers to an easy fit upon the teeth,-a fit so easy that you may put on and take off, and feel that it is without stricture and without friction. With delicate tweezers lay

them now-gently-in their waxy beds. As they lie there, harmonious in relation, harmonious in place, you may well exclaim, beautiful! beautiful!! Having filled up your impression with sand, plaster, and asbestos, and given an hour for setting, fasten your plate and clasps together with hard solder, and try them in the mouth. If you have been faithful to my directions you will know how much like true satisfaction a plate and clasps may be. With this achieved, pause not until the lost in nature is replaced by the restored in art, and the denture, once more complete, exists, a thing of use and beauty.-Dental Cosmos.

Hospital Reports and Case-Book.

PULPITIS AND PERIOSTITIS.

By J. J. MUSGRAVE, L.D.S. Glas.

I FBAR, from the number of cases I have met with, that the treatment of inflammation and other affections of the dental pulp is but little understood, and too frequently but carelessly undertaken, and thus resulting in the untimely sacrifice of teeth which, if diagnosed with a little more skill, and with the application of treatment suited to the diseased condition, could have been saved and rendered useful for their important functions; although no doubt the hasty determination of some patients, too eager to lose an offending tooth rather than endure the necessary remedial measures, is exceedingly trying to the equanimity of a Dental surgeon who desires to act conscientiously and with skilful results. However, to show that my introductory remarks forcibly apply to a certain number of registered practitioners, I will mention two typical cases.

CASE 1.-A lady consulted me a short time since about an aching and much decayed lower molar, and said that she had been to a Dentist a few days before to have the "nerve destroyed" with the intention of having the tooth "stopped," but that since the introduction of some substance which he had cemented in the cavity, her tortures had been indescribably severe. On the removal of the resinous wool and examining the painful tooth, it was not difficult to account for

the aggravated symptoms of my new patient's suffering, for evidently a very stupid and common mistake had been committed, i.e., "applying an escharotic for devitalising the pulp without careful attention that the pulp was thoroughly exposed." There was a thin layer of discoloured dentine and some débris of food (most likely mistaken for pus, resulting from a chronically inflamed pulp) over the pulp, consequently the arsenical application only reached it slowly and by infiltration. My treatment was to remove the layer of dentine and, on being satisfied that the alveolar dental periosteum was not sympathising, I applied a small quantity of" Clarke's pulp destroyer " (which is the most perfect and painless article of this description that I have ever used, and is vastly superior to arsenic and morphia, which I formerly used, and which, by the free acid it generally contained, was often productive of much irritation), and sealed it up with a pledget of wool dipped in an alcoholic solution of benzoin, directing my patient to call next day, which she did, saying that she had been free from pain. I reamed out the canals, filled them with wool dipped in a thin paste of "Fletcher's porcelain," and finished the crown with amalgam.

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CASE 2.-A medical man called in extreme agony from acute periostitis of an upper bicuspid, which was much enhanced by the blundering of one who had certainly more experience in the workroom than in the surgery, but who, on starting for himself, made use of the title "Dental Surgeon on his door-plate, and thus led the medical man to believe that he was qualified. This eminently skilful practitioner had applied arsenic to an empty pulp cavity in a tooth whose periodonteum was acutely inflamed. This case I relieved by clearing out the pulp cavity as well as I was able, and injecting a few drops of tincture of aconite, also dressing the canal with the same on wool and painting it on the surrounding gum, giving ten minims in water to be taken internally.

1, St. Domingo Vale, Liverpool.