paroxysmal, remittent or intermittent, and regular or irregular in its recurrence. It may come in flashes, and as suddenly disappear; or may continue a long time with little variation. Its varieties will be best considered under the different pathological conditions which it attends.

1. NERVOUS OR NEURALGIC TOOTHACHE.-A purely neuralgic condition. of the teeth is not uncommon. The affection may be seated in the nerve of a single tooth; but it much more commonly occupies the nervous trunk from which several teeth are supplied; and not unfrequently affects rather the jaw than the teeth themselves. The pain is in general of the acute character, sometimes mild in the beginning, gradually increasing in intensity, and as gradually declining; but usually very irregular, at one time moderate, at another severe, and occasionally darting with excruciating violence through the dental arches. Not unfrequently it assumes a regularly intermittent form. Instead of pain, strictly speaking, the sensation is sometimes of that kind which is indicated when we say that the teeth are on edge, and is apt to be excited by certain harsh sounds, such as that produced in the filing of saw teeth, by mental inquietude, and by the contact of acids or other irritant substances. Neuralgic toothache sometimes persists with intervals of exemption, for a great length of time, and becomes the torment of the patient's existence. The diagnosis is occasionally difficult. When, however, it occurs in sound teeth, is paroxysmal in its character, is attended with little or no swelling of the external parts, occupies a considerable portion of the jaw, and especially when it alternates or is associated with pain of the same character in other parts of the face, there can be little doubt as to its real nature.

This variety of toothache may depend on a morbid state of the nerve or nerves which are the immediate seat of it, but more frequently originates in a condition of the nervous system, such as disposes to neuralgic pains generally. This will be considered under the head of neuralgia. With an existing predisposition, it is sometimes invited by caries, but very frequently occurs in teeth which are perfectly sound. Almost anything which disturbs the system may serve as an exciting cause; but the most frequent causes are probably vicissitudes of weather, and the application of very cold or very hot substances to the teeth, especially in alternation. The disease appears to be sometimes sympathetic with morbid states of the stomach or other distant organs; and not unfrequently occurs in persons of a gouty or rheumatic diathesis.

Treatment. In plethoric cases with a strong tense pulse, general bleeding may be employed; but this is seldom necessary or advisable, and in cases of debility might aggravate the affection. In the latter cases, after due evacuation of the bowels, tonic medicines, especially the subcarbonate of iron, in doses of one or two drachms three or four times a day, and the sulphate of quinia freely administered, are often useful, and sometimes will effect a cure. The narcotics are also beneficial. The extracts of belladonna, stramonium, hyoscyamus, conium, and aconite, may be employed singly or in combination. Opium or some of its preparations are occasionally necessary to relieve the violence of the pain. When the neuralgic affection can be traced to sympathy with disease elsewhere, this should be corrected. Thus, antacids should be given in acidity of stomach, laxatives in constipation of the bowels, the blue mass or calomel in deranged or deficient hepatic secretion, aloes or other emmenagogue in amenorrhoea; and not unfrequently the co-existence of two or more of these affections calls for the simultaneous use of the appropriate remedies. If a rheumatic or gouty diathesis be suspected, wine of colchicum, hot pediluvia, and other means adapted to these disorders may be tried. Peruvian bark or sulphate of quinia will be found an almost certain remedy in re

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gular intermittent cases, and often useful in others. Mercury is sometimes effectual, when the disease has resisted all other treatment. In fact, whatever alters materially the distribution of nervous influence, and changes the condition of the system, offers a chance of benefit. Hence the employment of general frictions, and of cold and, hot baths, sometimes proves advantageous. In very obstinate cases, a total change of scene and habits is often highly beneficial. An excursion to some watering-place, a protracted journey, and especially a sea voyage, with long continued foreign travel, will often effect permanent cures when the catalogue of medicines has been exhausted in vain. The diet should be accommodated to the condition of the system, and of the digestive organs.

The local treatment consists of leeching in plethoric cases, anodyne embrocations or poultices, sinapisms and other rubefacient applications, frictions with veratria or strong tincture of aconite, blisters with a salt of morphia sprinkled on the denuded surface, moxa in the course of the nerves or on the side of the neck, cold water or ice to the cheek, steaming the face with the vapour of hot water, either pure or combined with volatile narcotics, tobacco fumigations, irritant and anodyne masticatories, errhines, electricity or galvanism, and all other topical means employed in the treatment of neuralgia. (See Neuralgia.) Chloroform, locally applied, will probably be found the most efficient anodyne. When a single tooth is affected, relief is sometimes afforded by its extraction; but this measure often fails, and always when several teeth are involved. Carious teeth should generally be removed in these cases, if the affection has proceeded far.

2. INFLAMMATORY TOOTHACHE.-This may exist with or without caries; but is in the great majority of instances dependent upon that affection. Before proceeding, therefore, to an account of its phenomena, it will be proper to say a few words on the subject of carious teeth.

Caries is an affection of the interior or bony structure of the teeth, the enamel being without vitality, and not therefore subject to morbid action. Some have denied to this disease a claim to the title of caries; because nerves and blood-vessels have not been traced in the substance of the teeth, and no process of absorption or granulation, by which the diseased part can be separated, and its place supplied by new structure, takes place. Thos. Bell, however, maintains that nerves and blood-vessels do exist, the former, because the tooth has a certain degree of sensation, the latter, because a red injection may occasionally be observed in its substance, and a yellowish colour is sometimes imparted to it in jaundice. (Bell's notes to Hunter on the Teeth.) There can scarcely be a doubt, that the bony portion of the tooth is organized, and is therefore subject to morbid action; and, though this may not present exactly the phenomena observed in caries of bones of a higher degree of organization, it approaches somewhat towards it in character.

Caries sometimes begins on the internal surface of the tooth, and extends outward, exhibiting usually, as the first evidence of its existence, a dark appearance beneath the enamel. (Good's Study of Med.) But, much more frequently, it proceeds from without inward, commencing in the bone immediately beneath the enamel, and exhibiting a yellowish or brownish spot in this situation. The tissue is softened, and a small cavity formed, which, after a time, communicates externally by the crumbling of the unsupported enamel over it. The substance of the tooth now decays more rapidly; and the caries, exhibiting a yellowish, brownish, or blackish colour, gradually approaches the central cavity of the tooth, which is at length opened. The caries is said to advance most rapidly in those cases in which the surface is yellowish. first there is little or no suffering; but, when the disease has reached the

At

cavity of the tooth, the pulp becomes sensible to heat, cold, and the action of irritant substances, and pain is experienced. At length inflammation takes place, which speedily advances to suppuration, and the pulp is gradually destroyed by ulceration or gangrene. The body of the tooth, deprived of the nourishment which it received from the pulp, decays entirely, leaving only the outer coating of enamel, which then breaks off by degrees, until nothing but the roots are left. These usually, though not always, cease to give pain. In some cases, especially when the surface is black or very dark, the caries advances very slowly, or is altogether arrested. In such cases, the surface is commonly also harder and less friable than in the yellowish caries. This decay of the teeth is not necessarily attended with pain. Occasionally the affection runs through its whole course, with little or no suffering to the individual; and sometimes, after having been painful, it ceases at certain periods of life to be so, though the process of decay may continue. In some instances of caries without toothache, the irritation appears to be felt sympathetically in other parts; and painful affections of the head, ears, and eyes, have ceased upon the extraction of a decayed tooth, which had never ached. I have seen violent and obstinate headache yield to the extraction of a tooth which had not been painful; and Dr. I. Hays, of Philadelphia, has described several cases of excessive photophobia which depended on the same cause, and yielded to the same remedy. In these cases, though the tooth may not ache, it will be found painful when pressed upon or struck smartly. (Trans. of Col. of Phys. of Philadelphia, ii. 411.)

The most frequent cause of caries is probably some condition of the bone acquired during its formation, in consequence of peculiarity of constitution, or the state of health existing at the time. Thus, persons affected with scrofula or scurvy, during dentition, are apt to be affected with decay of the teeth in after life. There is reason also to believe that the predisposition is sometimes hereditary. Women and young children are more subject to the disease than men. The direct or exciting causes are either such as destroy the integrity of the enamel, and thereby expose the bone to the influence of irritant substances, or such as operate directly upon its vital susceptibilities. Among the former are acids and other corrosive substances taken into the mouth, sour eructations from the stomach, depraved salivary or mucous secretions, the sordes which collect about uncleaned teeth, the contact or near vicinity of a carious surface in another tooth, the attrition of opposing surfaces of the teeth, and all kinds of mechanical violence. Of the latter, the principal are heat and cold suddenly applied, and especially in quick alternation. Hence it is, perhaps, in part, that caries of the teeth is more common in civilized life, where hot drinks are habitually used, than among savages. The very free use of sugar, as an article of diet, is thought by many to be a frequent cause of the disease. Some have ascribed its effects to direct action on the teeth; but it is more probable that it operates, if at all, by impairing digestion. Whatever deranges the digestive function may occasion caries indirectly, by giving rise to acrid and corrosive eructations, and by altering the secretions which are poured into the mouth. Nevertheless, sugar is certainly strongly irritant to the dental nerves; as is evinced by the severe toothache so often occasioned by its contact with a carious surface.

When the carics is slight, and especially when it occupies the sides of the teeth, it may often be arrested by removing the diseased portion with the file; and the same end may be attained by filling the cavity with some metallic substance, such as lead, tin foil, or gold leaf, so as to exclude the air and all irritant bodies. Plugging may be resorted to in all cases when the tooth has not begun to ache, or when it has ached but moderately and for a short time.

Having premised these remarks respecting caries of the teeth, we are prepared to enter upon the consideration of inflammatory toothache. It is proper previously to state that, in carious teeth, and in those deprived of their enamel without being absolutely carious, pain may be produced by the contact of irritant bodies, without the existence of inflammation. But the action thus excited, when not purely neuralgic, is an irritation which is the first step towards inflammation, and will inevitably lead to it if continued. The inflammation which occasions toothache may be seated in the pulp of the tooth, in the cord which enters its lower extremity, or in the periosteum investing its roots, and reflected over the interior of the alveolar cavity. Sometimes this inflammation terminates in resolution, without producing any swelling of the gum; and, in such cases, especially when the tooth itself is sound, the diagnosis is not easy between the inflammatory and neuralgic toothache. But the former is usually confined to one tooth, while the latter generally extends to several. Besides, the pain in the inflammatory variety is less sharp, less irregular, and less disposed to the paroxysmal form. Most commonly, however, after the pain has continued a short time, some external swelling appears. At first the pain is usually moderate, and it may continue thus throughout; but generally it increases, and at length becomes intense, in consequence probably of the pressure to which the swollen and inflamed parts are subjected by the unyielding bone around them. The tooth is at the same time very tender; and any force applied to it greatly increases the pain. The inflammation is propagated by contiguous sympathy to the gum and other parts of the face, which become much swollen; and the swelling sometimes extends to the salivary and absorbent glands, and even to the tonsils. The violence of the pain often abates somewhat upon the occurrence of this external inflammation, which appears to act as a revulsive. The tumefaction not unfrequently subsides without the occurrence of suppuration, and the toothache ceases for a time. Very frequently, however, an abscess forms either in the gum, upon the upper or lower jaw, in the roof of the mouth, or, more rarely, in the substance of the cheek. There is often much constitutional disturbance, with fever, headache, and inability to sleep. The pain, during the suppurative stage, is usually pulsative or throbbing. The abscess at length opens and relief is obtained. The duration of an attack of this kind is usually six or seven days, though sometimes much longer. When the abscess is seated in the palate, it is generally of slower progress, and sometimes continues for weeks or months without opening; but in the latter case the pain is not acute. The patient, though relieved for a time, is liable to constant returns of the affection in cases of carious teeth, until these are wholly destroyed in the course of the disease, or are artificially removed.

Suppuration also takes place in the pulp or dental cord. If an opening exist into the central cavity of the tooth, the pus may be discharged by this route; but, if there be no such outlet, the matter accumulating occasions inflammation and absorption of the socket, and thus makes itself a way out, either between the tooth and the gum, or directly through the latter, forming an abscess in its substance. When this opens, the pain is relieved; but the opening is apt to become fistulous, and a continual purulent discharge to be maintained until the tooth is wholly removed.

There is some distinction between the symptoms of the inflammation seated in the different parts above referred to. When it is in the pulp alone, the tooth is painful upon percussion, but suffers less when pressed against the opposite tooth, as in the closing of the jaws. The pain is often exceedingly severe, and is increased by hot and cold liquids taken into the mouth. Some

times, in these cases, a fungous growth projects through the carious cavity. This, if inconvenient, may be removed by excision or by caustic. When the inflammation occupies the cord, the pain is seated deep in the jaws, and is much increased by closing the teeth firmly. It may be dull or acute; but is less excruciating than that of the pulp, and is not equally affected by hot and cold liquids. When the tooth is extracted in these cases, pus is often discovered about the extremity of the root, and is sometimes collected in a small pouch. If the upper molar teeth are affected, the inflammation sometimes extends to the antrum, producing very serious results. When the periosteum of the root is the seat of inflammation, the pain is deep in the jaws, and the tooth feels elevated above its usual level, and is often somewhat loose. Closing the teeth is here also very painful. Rheumatic inflammation is apt to attack this part.

The most frequent cause of these inflammatory affections is the exposure of the pulp, consequent upon caries, or other destruction of the tooth. They may result also from vicissitudes of temperature, retrocession of cutaneous eruptions, the suppression of accustomed discharges, the translation of rheu matic or gouty inflammation from other parts, the pressure of osseous concretions in the cavity of the tooth, and from direct violence.

Treatment.-Little general treatment is requisite. Saline cathartics, and abstinence from animal food may be recommended when the inflammation affects the neighbouring parts; and an opiate at night is generally advisable when the pain is severe. The loss of blood may become necessary if there should be strong determination to the brain.

Much may be done locally to afford relief, and hasten the cure. The means are sedative, anodyne, and revulsive applications, and depletory measures, either within the mouth or externally. Among these remedies are brandy, or tincture of camphor, held in the mouth; the chewing or smoking of tobacco; various masticatories, such as ginger, calamus, pellitory, &c. ; poultices to the face, either simply emollient, or rendered anodyne by the admixture of laudanum, hops, &c.; anodyne lotions, as tincture of camphor with laudanum; rubefacient applications, as capsicum, ginger, and mustard in the form of cataplasm; blisters to the side or back of the neck, or behind the ears; steaming the face and head with the vapours of hot water; scarification of the gums; and, finally, leeches outside of the face or to the gums, when the inflammation is considerable, and it is deemed highly desirable to bring about resolution. In most cases, the milder of these means are sufficient; as the disease is generally soon relieved by suppuration, and the discharge of the pus. After the abscess has formed, it should be opened if it do not speedily discharge itself; and, if it occupy the substance of the cheek, care should be taken to make an early opening inwardly, lest it might break externally and leave an unsightly scar. When caries exists, in addition to the means just mentioned, applications may be made to the cavity of the tooth itself. These are usually such as relieve pain by their anodyne, or obtund sensibility by their excessively irritant action. They consist chiefly of laudanum or opium, in reference to the former effect; and of certain volatile oils, as those of cinnamon, cloves, and cajeput, in reference to the latter; all of which should be introduced on cotton. The most efficient of these applications, in the experience of the author, is ereasote. Put undiluted into the carious cavity, this substance not only relieves, but also for a time often effectually cures toothache. It probably acts both by obtunding the sensibility of the pulp, and by coagulating any albuminous matter which may be present, and thus forming a barrier against the external air. A solution of copal in chloroform has been strongly recommended. The chloroform relieves the pain, and the copal, by its adhesiveness, retains the