believe, borne out by practical observation) would certainly point to a constitutional origin of the disease, and to a common origin which is neither the epidemic of small-pox, scarlet fever, or other exanthem, but a much more general epidemic, I mean syphilis.

Do then the eruptive diseases exert any influence on the teeth or their adjoining structures? I think we may say in this day, that if these diseases are let alone, or rather if they are not over-treated, humanity is pretty well saved from their aftereffects in so far as the organs of mastication may be considered. But there is unquestionably one of them which did in old time, and before the era of one of our immortal countrymen and science-brothers, leave its impress on all organs, and on those of mastication not the least.

In the palmy days of small-pox, the concurrent testimony of all authors is to the effect that the poison of this disease, like that of mercury, left behind it special dental maladies, consisting chiefly in inflammation of the periosteum, exfoliation of the alveolar process, and loss of teeth. One can scarcely, indeed, recall or accredit such histories as the following one written in the present century by Mr Fox.

"In the excellent museum of Mr Heaviside are several specimens of exfoliations which have been occasioned by the deadly operations of that loathsome pestilence.. This very curious exfoliation is from the under jaw of a little boy, of about four years old, from matter formed between the gums and the bone after small-pox. As soon as it became pretty loose, the whole was carefully removed, and shows itself to be the substance of the lower jaw with some teeth in it. A small portion of the anterior part of the upper jaw also exfoliated, with two of the incisor teeth and two secondary teeth."

There can, I repeat, be no hesitation in accepting the fact that this one of the epidemic diseases produces material injury to the teeth; but I would again repeat, from my observations of the infantile diseases, that they have much less to do with the production either of atrophy of the teeth, dental gangrene, or necrosis, than is ordinarily presumed to be the fact in works on dental surgery. I find Professor Bell, for instance, stating that the whole list of infantile diseases operating during the forma tion of the permanent teeth are to be considered as so many causes predisposing to gangrene. And again I find him naming fever, by which I presume he means typhus, and which fever, like the exanthems, depends on specific poison, as a cause of dental necrosis. Now I take it from observation of these diseases and their effects, rather than of the after effects attributed to them, that the effects are not due to the diseases themselves, but when isolated from pre-existing syphilis, are due rather to a mercurial treatment pursued for the cure of the diseases. This at all events is my experience: that when in public practice children are brought to me in whom the atrophied tooth or the

carious tooth are markedly present, the first on inquiry resolves itself into a syphilitic origin; the second, though often attributed to measles, to scarlet fever, and the like, to a mercurial origin.

Certain it is, on the other hand, that the whole of the infantile diseases (small-pox excepted) may occur during the formation of the permanent teeth, and yet a set of permanent teeth may follow as perfect as may be desired. I shall on another occasion refer to the remarks of Mr Salter on these subjects.

I have alluded incidentally, on several occasions, to syphilis as a constitutional source of dental disease. I cannot over-estimate this subject. We know in these days that the origin of the disease is in specific poison, and we know the mode in which it is communicated, although in the sixteenth century many doubts surrounded this very simple subject, and syphilis, like other epidemics, was attributed to atmospheric changes, the influence of the stars, and such like agencies. We see now that the poison does not stop with those whom it first attacks, but is transmissible on from parent to offspring, stopping, perchance, not at the first generation. We observe that through either parent the disease may be produced, and we prove the influence of this fact by the circumstances that the large majority of children prematurely born and still-born, are so born as a consequence of syphilis, and that out. of 88,784 children dying in England in one year from all causes, no less than 255 die from syphilitic disease.

The peculiarity of the syphilitic virus consists in two facts (I am speaking now only of its secondary effects), first, that it acts as a general poison, suppressing the nutrition of all parts, and secondly, that it leads to special derangement of nutrition in the osseous and fibrous textures of the body. I do not think it yet proved that syphilis contracted in adult life, and taking its unimpeded course, interferes materially with the dental structures, for here again the influence of mercury in the treatment comes into play so often that it is difficult to separate the effects of one poison from the effects of the other.

In reference to the effects of the syphilitic poison on the development of both the temporary and permanent teeth, the influence is undeniable, and I think it possible that there is scarcely any chronic disorder of the dental structures which is not influenced more or less by the effects of the syphilitic diathesis, when this is present. But there seems also to be a special affection of the teeth due to the hereditary syphilitic disease. This subject has lately been investigated with considerable care by Mr Jonathan Hutchinson, who has arrived at the conclusion that there is a peculiar condition of teeth which results from the influence of hereditary syphilis, and that the most frequent features of the condition are the following: A, smallness of teeth; B, notching; C, colour, which is a dirty grey; D, wearing down; E, a confinement of these signs almost entirely to the incisors

and canines. These symptoms only apply to the permanent set of teeth, according to Mr Hutchinson, who accounts for this by supposing that the temporary set suffer less uniformly than the permanent, because the occurrence of syphilitic stomatitis and its complication with alveolar periostitis to which the marring of the tooth is attributed, occurs during the first weeks of life, and when the temporary set of teeth are already well formed. Mr Hutchinson gives two very decisive cases in which, during syphilitic stomatitis in infants, inflammation of the alveolar periosteum accompanied by exfoliation of the teeth took place. These conditions of the teeth, which will be recognised by the dental profession as tallying very closely with what has been called atrophy of the teeth, are entirely distinct from caries, although such teeth are very liable to caries. The opinions brought forward by Mr Hutchinson, submitted to a committee of the Pathological Society of London, were in great measure confirmed by the committee. I look upon it that they may be accepted as representing in a very defined way, and from a very definite cause, a particular kind of dental disorder, though I would not agree with Mr Hutchinson, that a patient born syphilitic may escape from damage of the teeth altogether, if in infancy he escape stomatitis.

In cases of acquired syphilis, indeed, we often see not only a destruction of the teeth from exfoliation, but a residual effect on these organs creeping on assiduously, and manifesting itself at last in a manner as unexpected as it is serious.

We have yet to notice briefly the third class of poisons which, through the system, implicate the teeth. I spoke of these poisons as malarious poisons. That these poisons or it were perhaps nearer the truth to say this poison, the evidence being in favour of a unit poison-acts only through the system is clear from the fact, that it produces general systemic symptoms of an intermittent kind, of which the tooth symptom is often but one, though it may be for the time the only symptom. How this poison finds its way into the system is a point of great obscurity. There is strong evidence that it floats in the air, and is inhaled by the lungs. There is strong evidence that it is sometimes carried by impure water, and is absorbed by the stomach. In its intensity of action it is confined to particular districts of the country-to marshy districts of country, of all others -where it lights up endemic disease. But in lesser intensity the poison lurks everywhere, setting up neuralgic affections, and tooth neuralgia perhaps most of all. Often when least suspected, this poison is doing its silent work, and teeth are not unfrequently sacrificed to its fury which in structure are as sound as unbroken enamel or dentine can make them. I remember some years ago being peculiarly impressed with this fact. In a village in which my professional labors were once exercised there was a small plot of ground covered with houses and little gardens. During

one season I was constantly having under treatment some of the inhabitants of this locality for the toothache. I am afraid that, under pressure of solicitation and in ignorance of the cause that was at work, I drew more sound teeth than diseased ones for the people of this place. In the ordinary course of professional practice, the origin of the malady did not at first engage attention. At length an adult male inhabitant of the place came to me, not with toothache, but with brow ague. He remained under treatment some time, and, though relieved by quinine, did not recover. He went to one of the London Hos

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pitals, and was very properly advised to try change of air. took the change for a week, and had no sign of his disease. returned home, and the disease at once returned to him. The same process was again repeated with the same results. On his after report of these facts to me, I was led to attribute this disease, and the recurring attacks of others in the locality, to some central and local cause. The cause once looked for was soon found, in the shape of a common, foul, and untrapped drain, the mouth of which was the open cloaca for the district. The drain emptied and cleansed, all the cases of neuralgic pain disappeared.

From this we learn that the source of this poison may be quite local, that the poison requires constant renewal for the manifestation of its effects, and that the body once removed from the main source soon eliminates the poison from itself.

From those diseases of a constitutional nature which arise from poison introduced into the body and thence by secondary effect produce local diseases of the organs of mastication, we may turn to the second class of constitutional diseases which arise, as I have said, not from direct introduction of poison, but from some external or general cause hereditary or acquired, by which the physiological functions are deranged and health impaired. In this list of diseases are included certain states of body which are ordinarily grouped as diatheses, from the circumstance that they admit of arrangement under certain common heads and indicate at once a general disposition of one individual body to the development of one individual disorder. In this way we speak of the inflammatory diathesis, the strumous diathesis, the gouty diathesis, and the like. I shall consider such of these general dispositions as appear to give a constitutional basis to dental maladies.

The strumous or scrofulous diathesis has been treated of by most writers on dental surgery as one of the most common causes of caries, and the teeth of scrofulous persons have been specially described as small, of pearly whiteness, fragile, and ready to decay. In medical practice this disposition to dental mischief does not, however, come out so strikingly as might be supposed, nor do other diseases of the masticatory organs seem to the physician so simply dependant on struma as has been assumed. I doubt not that the practitioner of dentistry frequently

meets with cases of strumous disease in which the teeth are specially implicated; the case therefore coming before him with all the marks of strumous disease prominent, he is led to connect the local disorder as an effect, to the strumous disorder as a cause. The physician, on the other hand, with his mind fixed on the general disorder, is often surprised to observe, amidst all the havoc which struma inflicts on its victims, how wonderfully the teeth escape. If we connect the disease phthisis pulmonaris with the strumous diathesis, the extent to which the teeth escape in the midst of surrounding evils is at once a remarkable and important fact. Amongst the numerous cases of consumptive disease which pass before me in an institution specially devoted to the treatment of that complaint, I do not remember a single instance in which there was any marked pe. culiarity; such as would specify a constitutional derangement, acting so as to affect the dental organism, either by caries, necrosis, or atrophy.

Yet there are two points relating to phthisis which deserve notice. When phthisis is fully developed, and that marked phenomenon of its presence, the intermittent hectic, shows itself, one symptom is often complained of as accompanying the attack-I mean a severe tooth neuralgia. The mention of this has led me often to examine the teeth of a phthisical patient, but such examination has rarely given a clue to the disease; indeed the pain is not concentrated in one tooth, but extends often to one side of the jaw altogether, and is not always in truth confined to the same side, but moves about, thus demonstrating its general origin. Large doses of quinine relieve this affection better than any other remedy, for the relief of which I have known teeth uselessly extracted.

In children of strumous habit, living in close unventilated rooms and subsisting on insufficient food, the soft parts surrounding the teeth are however very subject to ulceration, and the disease cancrum oris seems indeed to depend in great measure on the strumous diathesis, aided unquestionably by the external circumstances, and this ulceration extending deeply does indirectly involve the alveolar process, and so leads to disconnection and destruction of the teeth themselves. But here the tooth disorder is the indirect, and I had almost said accidental, result of a constitutional disease.

Those characteristic affections of the bones designated rachitis and mollities ossium, to which the children of strumous parents are so susceptible, might lead an observer given to compare analogies of structure with analogies of morbid structure to the belief that a connexion with the strumous diathesis with dental disease was common and sequential. But analogy fails equally in this case, a failure which the distinguished Hunter was first to point out. He observed that children and adults suffering from these disordered conditions of the bones rarely, if