Fabricius also speaks of dental prosthesis, but very briefly. He says that artificial teeth are made of ivory or of bone (for example, from the tibia of the ox) and are fastened by gold wire. One has recourse to this means especially to correct the bad appearance and the defects in speech deriving from the loss of the front teeth. This author also makes some allusion to palatal obturators,[324] but in very general terms, limiting himself to saying that when a perforation exists in the hard palate, it may be corrected by a piece of sponge or cotton, or with a plate of silver fixed in the palate, so as to close up the aperture (_corrigitur spongia, vel gossypio, vel lamina argentea, quæ palato appendatur, ut foramen obstruat_). For epulides and parulides Fabricius advises the same methods of cure that had been recommended by Paul of Ægina. In the case of flaccidity of the gums accompanied by looseness of the teeth, the treatment must consist, first of all, in superficial cauterization with the red-hot iron, after which the gums must be smeared with honey, the mouth washed with mulse, and lastly astringent powders must be used. If the gums are much swollen, in near relation to the molar teeth, the use of the red-hot iron, says Fabricius, becomes very difficult from the want of space, and from the close vicinity of the healthy parts, which must not be injured. In such a case, it is necessary to remove, with suitable cutting instruments, as much as is possible of the morbid tissue (_caro crassa et putrida_); then to cauterize the remaining part, making the cautery, if necessary, pass through a tube, so as not to injure the surrounding parts. When, however, the gingival swelling bleeds very easily, and its excision thus might give rise to a profuse hemorrhage, it will be best to perform the operation with cutting instruments heated red-hot. Fabricius remarks that although other authors do not make any allusion to these large gingival excrescences, he had had occasion to observe several cases, and had also had various instruments especially constructed for their cure.[325] JOHANN HEURN, or in Latin Heurnius (1543 to 1601), of Utrecht, in his book on the diseases of the eyes, ears, nose, teeth, and mouth, treats sufficiently at length of dental diseases and their cure, but without adding anything of importance to what had been written by preceding authors. His work is a mere compilation, which would be without any importance whatever if it did not serve to show what credit was still given at that period to all the errors and prejudices which are to be found in the writings of the ancients. Heurnius, although he wrote a long time after Vesalius, still adheres, in regard to the number of teeth, to the already mentioned opinion of Aristotle; he says, in fact, that women rarely have thirty-two teeth like men.[326]