demoniacal possession, which probably includes, in the language of that age, cases of madness, deep melancholy, epilepsy, and other diseases, by the invocation of the name of Jesus. Justin Martyr speaks of such cures as a frequent occurrence in Rome and all over the world, and Origen appeals to his own personal observation; but speaks in another place of the scarcity of miracles, so as to suggest the gradual cessation theory, as held by Dr. Neander, Bishop Kaye, and others. Tertullian attributed many, if not most of the conversions of his day to supernatural dreams and visions, as does also Origen, although with more caution. But in such psychological phenomena it is exceedingly difficult to draw the line of demarkation between natural and supernatural causes, and between providential interpositions and miracles proper. The strongest passage on this subject is found in Irenæus, who, in contending against the heretics, mentions, besides prophecies and miraculous cures of demoniacs, even the raising the dead among cotemporary* events taking place in the Catholic Church. But he specifies no particular case or name; and it should be remembered, also, that his youth bordered yet almost on the Johannean age.

4. The MORAL EFFECT of Christianity upon the heart and life of its professors. The Christian religion has not only taught the purest and sublimest code of morals ever known among men, but actually exhibited it in the life, sufferings, and death of its Founder and true followers. All the apologists, from the author of the Epistle to Diognetus down to Origen, Cyprian, and Augustine, bring out in strong colors the infinite superiority of Christian ethics over the heathen, and their testimony is fully corroborated by the practical fruits of the Church. "They think us senseless," says Justin, "because we worship this Christ, who was crucified under Pontius Pilate, as God next to the Father. But they would not say so if they knew the mystery of the cross. By its fruits they may know it. We who once lived in debauchery now study chastity; we who dealt in sorceries have consecrated ourselves to the good, the increate God; we who loved money and possessions above all things else, now devote our property freely to the general good, and give to every needy one; we who fought and killed each other now pray for our enemies; those who persecute us in hatred we kindly try to appease, in the hope that they may share the same blessings which we enjoy."+

5. The RAPID SPREAD OF CHRISTIANITY by purely moral means,

* Adv. her. I. 31, § 2, and I. 32, § 4 : ἤδη δὲ καὶ νεκροὶ ἠγέρθησαν καὶ παρέμειναν oùv пμiv ikavois trεσl. These two passages can hardly be explained, with Heumann and Neander, as referring merely to cases of apparent death.

† Apol. I. c. 13 and 14, (p. 35 sq. ed Otto.)

and in spite of the greatest external obstacles, yea, the bitter persecution of Jews and Gentiles. Origen makes good use of this argument against Celsus, and thinks that so great a success as Christianity met among Greeks and barbarians, learned and unlearned persons, in so short a time, without any force or other worldly means, and in view of the united opposition of emperors, senate, governors, generals, priests, and people, can only be rationally accounted for on the ground of an extraordinary providence of God and the Divine nature of Christ.

6. The REASONABLENESS of Christianity, its agreement with the intellectual wants of man, and with all the true and the beautiful in the Greek philosophy and poesy. All who had lived rationally before Christ were, in the opinion of Justin, really, though unconsciously, already Christians. Thus all that is Christian is rational, and all that is truly rational is Christian. Yet on the other hand, of course, Christianity is supra-rational, not irrational.

7. The ADAPTATION of Christianity TO THE DEEPEST NEEDS OF HUMAN NATURE, which it alone can meet. Here belongs Tertullian's appeal to the "testimonium animæ naturaliter Christianæ ;” his profound thought that the human soul is, in its inmost essence and instinct, predestined for Christianity, and can find rest and peace in that alone. The soul, says he, though confined in the prison of the body, though perverted by bad training, though weakened by lusts and passions, though given to the service of false gods, still no sooner awakes from its intoxication and its dreams, and recovers its health, than it calls upon God by the one name due to him: "Great God! good God!" and then looks, not to the capitol, but to heaven; for it knows the abode of the liv ing God, from whom it proceeds.* This deep longing of the human soul for the living God in Christ, Augustine, in whom Tertullian's spirit returned purified and enriched, afterward expressed in the grand sentence: "Thou, O God, hast made us for thee; and our heart is restless till it rests in thee."†

Tert. Apolog. c. 17. Compare the beautiful passage in De testim. animæ, c. 2: Si enim animæ aut divina aut a Deo data est, sine dubio datorem suum novit, et si novit, utique et timet.... O testimonium veritatis quæ apud ipsa dæmonia testem efficit Christianorum.

August. Confess., 1. i, c. 1: Fecisti nos ad te, et inquietum est cor nostrum, donec requiescat in Te.

ART. IX-POPULAR DENTAL KNOWLEDGE.

FROM all accounts, in ancient Egypt dentistry seems to have originated as a separate branch of the healing art; and as in all old countries the profession or calling of the father generally descended to the son, there is no reason why this branch should not in time have made great progress under those to whose care it was committed, or at least that part appertaining to tooth extraction. And from the fact that among Egyptian remains there have been found forceps made of copper in the offices of those who followed the occupation of barbers, it may be inferred that to those persons, as for centuries after in various countries, the operations on the teeth were intrusted.

From the writings extant of the early physicians, and authors of works on anatomy and physiology, it would appear that their knowledge of the structure and diseases of the dental organs was extremely limited and erroneous; and as all knowledge was more or less under the jurisdiction of the seers, prophets, and priests, who controlled both the social and religious opinions of those days, we can readily account for such an idea as was advanced by Arætacus, that the cause of toothache was only known to God. Five hundred years before Christ Herodotus, the traveler and historian, informs us that the Egyptian physicians divided the healing art into different parts, one taking that of the head, another the eyes, another the teeth, etc. The mode of extracting practiced and recommended by some of the earlier practitioners was, to shake the teeth well, and then remove them. Others advised the application of the hot iron, or boiling oil, to make them exfoliate; but it is unnecessary here to enumerate the absurd practices recommended. And although, during the lives of Socrates, Plato, Aristotle, Herodotus, Thucydides, Eristratus, Celsus, Pliny, Galen, and others, the healing art may be said to have made great advances, the state of dental surgery remained nearly the same. Little or no change, in fact, took place for the better until about the time of the great anatomist John Hunter, of England, who published his work on the teeth in 1778. He has since been followed by numerous other authors and practitioners, both European and American, who by their labors and researches, combined with anatomical and physiological erudition and mechanical skill, have elevated dental surgery to a high position among the arts and sciences of the present day. The last half cen

tury has witnessed the operations on the mouth that were formerly left to the care and tender mercies of the ignorant knight of the razor and shears, assumed as a calling by men of education and refinement; and the world at large acknowledges its indebtedness to the dental surgeon for that comfort and happiness that can only be derived from a healthy condition of this part of the animal economy, without which the "Hell of all diseases" would reign supreme, for who that has suffered from the pains of an aching tooth and its direful concomitants would say that it was the least of the "ills that flesh was heir to?"

The student and practitioner of this branch of the healing art now takes his position beside the student and practitioner of medicine. Dental surgery has now its colleges and its quarterly and monthly periodicals, presided over and edited by men who, by their learning and skill, take the highest rank among the profession of their choice; and the degree of D.D.S., Doctor of Dental Surgery, as truly indicates having passed through a regular course of scientific preparation as the degrees of A.M. or M.D. in other professions. Twenty five to thirty years only have passed since the vail of secresy has been removed from dental operations. Previous to that time the dentist hid his operations from his brother practitioner. His female patients, with faces concealed and hesitating steps, groped their way with secrecy to his door, not desiring to have it known that they needed or were obliged to wear artificial teeth. But a few years have passed since a few dentists only were to be found in any of our large cities; now our city dentists are numbered by hundreds, while every village or country town has one or more as a permanent fixture. Eighteen years ago the first dental college established in the world had its origin in the city of Baltimore; since which time there have been three others, one in Philadelphia, one in Cincinnati, and one in Western New-York. These institutions have professors of dental surgery, dental medicine, anatomy and physiology, dental mechanics, dental practice, chemistry, and metallurgy; also lectures on microscopic, and comparative anatomy of the teeth.

So much for the origin and progress of dentistry. We will now attempt to place before our readers the practical part in such a manner that we hope may enable every individual not only to keep in good preservation their own dental organs, but those of other persons intrusted to their care. Every one should be familiar with the fact, that the decay of the teeth always commences externally, or in other words, decay always shows itself upon the enamel, or bony structure of the teeth, and never internally, as was at one time supposed to be the case. It may be said to be in most cases the result of chemical

action, produced by the decomposition of particles of food that collect or lodge in the interstices or depressions of the teeth, while eating These fissures are caused by the imperfect uniting of the edges of the enamel while the tooth is being formed; any individual can readily detect them on examination. Every one will, therefore, readily see how necessary it is to prevent all particles of food or foreign matter from remaining a sufficient time to produce decomposition. Numerous experiments have been instituted for the purpose of ascertaining the length of time necessary for various kinds of food to so decompose as to produce injury. All food in a state of decomposition generates an acid. From experiments by Professor Amos Wescott, it was found that "acetic and citric acids so corroded the enamel in forty-eight hours that it could be readily removed with the finger nail. Acetic acid, or common vinegar, is one of our principal condiments, and he says is "formed in the mouth whenever substances liable to fermentation are suffered to remain for any considerable length of time."

Citric acid, or lemon juice, of which many, especially young females, are so fond, readily acts upon the lime of which the teeth are composed, when brought into contact with them. Malic acid, or the acid of apples, in its concentrated state, also acts promptly; also muriatic, sulphuric, and nitric acids, although greatly diluted. And here let us caution all persons against using any preparation to whiten the teeth; for as the teeth are mostly composed of phosphate and carbonate of lime, anything that produces this effect acts on their material, and will ultimately seriously injure or destroy them. Keep the teeth clean, and they are as white as nature intended. Professor Wescott also found that "raisins so corroded the enamel in forty-eight hours that its surface presented the appearance and consistency of chalk." The condition of the saliva is also, at times, very acidulous. In view of what we have above stated, it will be seen how careful every one should be, for self or for children, thoroughly to cleanse the teeth from all substances that come in contact with them.

Preparations for cleansing and purifying the mouth should be free from all acids, and contain, as one of the principal ingredients, an alkali, (such as enters into saponaceous substances,) to neutralize the acid, and destroy the animal and vegetable parasites that are secreted by the fluids of the mouth. It has been found by microscopical examination, that the secretions of almost every person's mouth contain more or less of vegetable and animal life that will withstand the application of acids and astringents, and will only succumb to alkalies, which not only appear fatal, but a preventive