FR. A. GERAULDY, a French dentist, wrote (1737) an excellent treatise on dental maladies and on the mode of preserving the teeth. His book, which was also translated into German,[473] contributed to the diffusion of knowledge relative to dental prophylaxis and therapeutics, but apart from this brought no increment to the progress of practical dentistry. Some of the ideas of the author, however, merit consideration. He clearly expresses the opinion that the shedding of the milk teeth is brought about by the pressure exercised upon them by the germs of the permanent teeth in course of development. The loss of the teeth in young subjects, or in those who have not yet reached forty years of age, is explained by the author in an altogether special manner. He relates that Louis XIV, at the age of thirty-five, had lost all his upper teeth, and the considerations he makes on the subject bring him to the conclusion that the precocious loss of the upper teeth depends in many cases on a paralysis of the nervous fibers that go to them, which paralysis is probably caused by a dissolute and intemperate life, having as its consequence the weakening of the organism and, above all, of the nervous system. Without doubt there is some truth in Gerauldy’s ideas, it being well known that the falling of the teeth (as well as of the nails and the hair) often depends on nutritive disorders deriving from nervous disturbances. We have the clear proof of this in certain cases of tabes dorsalis accompanied by the spontaneous falling of the teeth and nails. JOSEPH HURLOCK, an Englishman, published a treatise in 1742,[474] in which he warmly recommends lancing the gums in cases of difficult dentition; he declares this to be entirely without danger, and affirms that it constitutes the sole means of salvation for not a few infants who without it would die of convulsions. MOUTON, in 1746, that is, in the same year in which the second edition of Fauchard’s work was issued, gave to the light a monograph, the first extant, on mechanical dentistry.[475] The methods of this author for the most part do not differ from those of Fauchard, nevertheless one finds several important innovations in his work. To prevent the further deterioration of teeth already much destroyed, and to preserve them some time longer, Mouton had recourse to the application of “calottes d’or,” that is, gold crowns. He used this for the front teeth as well as for the molars, but in the former case he had them enamelled to give them the same appearance as natural teeth. Mouton also invented a new method of applying artificial teeth. Up to then the ordinary method had been that of fixing them to the natural teeth by means of threads passed through holes made in the artificial teeth expressly for that purpose. Mouton is the first to speak of artificial teeth fixed to the natural teeth adjoining them by means of springs or clasps.