JACOB CHRISTIAN SCHAFFER. In 1757 the evangelical pastor, J. Ch. Schaffer (we do not know if he was at the same time a dentist, or merely an amateur in odontology), wrote a little book[483] to disprove the existence of worms in decayed teeth, and to show the fallacy of believing that the supposed worms may be made to drop out by means of fumigations of henbane seeds. His book appeared, as a matter of fact, rather behind-hand, for in it Schaffer repeats in substance what Houllier had already said two centuries earlier, and after him various other authors, including Fauchard. At any rate, to coöperate in the complete destruction of error and in the diffusion of truth is always laudable. We feel, however, bound to add that in the very same year in which Schaffer’s pamphlet was published, DUFOUR, a Frenchman, described a worm that had been taken out of a decayed tooth, and called attention to the fact that it was altogether different from the “dental worms” described by Andry.[484] BOURDET. An excellent book on dentistry[485] appeared in France in the year 1757, the work of Bourdet, a celebrated dentist and elegant writer, in whom the gifts of literary and scientific culture were coupled with a vast experience and a profound spirit of observation. His merits procured him the honor of being appointed dentist to the King. This author condemns as harmful the use of hard substances (such as bone rings, etc.) that people are in the habit of putting into children’s hands during the period of the first dentition, in the idea that by pressing these objects between the gums, as children instinctively do, they cut their teeth more easily. As to emollients, he holds them to be completely useless, and prefers to all these remedies the use of lemon juice. According to Bourdet, the teeth are so apt to decay, partly because of the frequent changes of temperature to which they are exposed, and partly because, differently from the bones, they are not provided with any protective organic covering. In many cases of caries, Bourdet extracted the tooth, filled it with lead or gold leaf, and replanted it; but if, in extracting, the alveolus had been somewhat injured (a thing very likely to happen with the instruments of the period), he replanted the tooth immediately, to preserve the alveolus from the damaging action of the air, and carried out the stopping at a later time.