The second part of the work is dedicated to the other diseases of the maxillary bones (especially of the inferior one), as well as to those of the lips, cheeks, salivary ducts, gums, frenum linguæ, etc. Dental hemorrhage and difficult dentition are also spoken of in this volume. The author relates, with regard to the latter subject, that he had observed, in corpses of infants who had succumbed to a difficult dentition, that the crowns of the erupting teeth were covered by the alveolar margins folded upon them. This, according to him, must be the reason why even lancing of the gums proves useless in some cases of difficult dentition; it is therefore necessary, whenever it is possible to recognize the existence of this state of things, to destroy the bony margins that oppose the erupting of the teeth; the author declares that he has frequently done this, with fortunate results. In 1784 Jourdain published a treatise on artificial dentures.[492] He therein specially speaks of a complete denture with four springs, perfectly adapted to the purpose of mastication. The author attributes the merit of its invention to MASSEZ, who had imagined it toward 1772. If we may judge, however, by what Joseph Linderer says,[493] this denture appears to have been too complicated, even when compared with those described by Fauchard. LAMORIER and RUSSEL, contemporaries of Jourdain, also studied the diseases of the maxillary sinus, and published in the _Mémoires de l’Académie de Chirurgie_, vol. iv, several important cases of polypi and other diseases of the antrum. Lamorier is not in favor of the Cowper-Drake operation. He recommends perforating the antrum immediately above the first molars, or rather between it and the malar bone. In this he seems to have been influenced by the considerations that the wall of the cavity here presents the least thickness, and that this is the most dependent part of the sinus. But he did not always deem it necessary to make a perforation here, when a fistulous opening had previously formed in some other place. His method of operating is as follows: The jaws being closed, the angle of the mouth is drawn outward and slightly upward with a curved instrument called by the author a speculum; this done, the gum is incised below the molar apophysis and the bone laid bare, and then pierced with a spear-pointed punch. The opening is afterward enlarged if found necessary.