Pelicans for extracting wisdom teeth (Campani).] With regard to incision of the gums, in cases of difficult dentition, this author contradicts certain assertions of the German surgeon Isenflamm (1782), who argued that when the tooth is already to be perceived through the gum, the incisions are altogether useless, while if the tooth be still at some depth, the gingival incision will soon close again, so that the cicatrix will render the eruption of the tooth still more difficult. Bell admits, too, that lancing the gum is altogether superfluous when the tooth has pierced the tissue, all the more so that the accidents provoked by the eruption are then generally already passed and gone, but the operation ought, in his opinion, to take place much earlier; and should the wound close again before the tooth has erupted, the gum must be lanced a second time. [Illustration: FIG. 98 Campani’s forceps: The first for molar teeth when loose or after having been shaken with the pelican; the second for deciduous teeth.] Bell contradicts the opinion of Jourdain and Hunter that the morbid gatherings of Highmore’s antrum are generally consequent upon the closing of the normal opening of the cavity in the middle meatus. In many cases of disease of the maxillary sinus this orifice remains open, the liquid therein collected discharging itself not unfrequently through it, in certain positions of the body. Instead of penetrating into the antrum through the nasal orifice, as Jourdain would have it, Bell advises opening the cavity by Lamorier’s, or, better still, by Drake’s method. Except in special cases, the first or second molar ought to be extracted, but preferably the second. After trepanning the alveolus and emptying the cavity, the opening should be closed with a conically shaped peg to prevent its slipping into the cavity. From time to time the liquid that tends to reaccumulate should be allowed exit, and detersive injections should be made, preferably of lime water. [Illustration: FIG. 99 Two key instruments with changeable hooks (Campani).] Looseness of the teeth, which in old age may be considered a normal condition, is always a disease when it occurs in youth. In certain cases its cause is unknown, in others it depends on an affection of the gums, either of a scorbutic nature or consequent on an accumulation of tartar. [Illustration: FIG. 100 An instrument especially destined to extract loose bicuspid teeth. The screw in the interior of the instrument allowed the hook to be brought to just the right point in each case (Campani).] According to Bell, dental caries is generally owing to a bad condition of the humors of the entire body and to a peculiar morbid disposition, rather than to external causes acting locally, although these latter may contribute, together with the general causes, to the producing of the disease. [Illustration: FIG. 101