PIERRE AUZEBI, a dentist at Lyons, published a treatise on odontology in 1771, which is only remarkable for certain strange ideas that he therein exposes, the entire book being in complete contradiction with the great progress already realized, at that period, in dental science. Auzebi likens the human body to a hydraulic machine, formed by the union of solid and liquid parts. For him the bones are merely _folded membranes_ and the teeth are _bones composed of small membranes_. The author declares that he is unable to admit the theory of germs in the genesis of the teeth because “these germs, being all in identical conditions as to heat and moisture, ought all to develop at the same time like the grains of corn in a field.” Rather than having their origin from special germs, the teeth, he says, are derived from lymph, this being, according to Auzebi, the fundamental substance from which all the hard parts of the body are generated. A drop of lymph gathered at the bottom of the alveolus hardens and constitutes the first beginning in the formation of the teeth. Beneath this other lymph is gradually collected, which pushes upward and the part of the tooth already formed, surrounds the dental vessels, and thus becomes the root of the tooth. To facilitate dentition he recommends, among other things, rubbing the gums with hard, rough, and angular bodies. He also maintains, as does Brunner, that the milk teeth have no roots, contradicting, in this respect, the opinion of Fauchard, of Bunon, of Bourdet, who decidedly affirm that the deciduous teeth are furnished with roots, precisely the same as the permanent ones. According to him, when it so happens that the milk teeth have roots, they are not shed. To calm toothache, the author recommended a sedative elixir, the aspirating of a few drops of which sufficed to obtain the desired effect.[510] JOHN AITKIN, in 1771, perfected the English key, so as to render the extraction of the teeth easier and to avoid the danger of fracturing the alveolus or the tooth itself, and of injuring the gums.[511] FRÈRE CÔME, a celebrated French surgeon, also contributed to the perfecting of this instrument.[512] In 1771-72, Fr. L. Weyland and Henkel recorded some very important cases of diseases of Highmore’s antrum.[513] W. BROMFIELD, in a collection of surgical observations and cases published in London in the year 1773, also speaks of affections of the maxillary sinus. He says that he has had opportunity of persuading himself that the purulent gatherings of this cavity not unfrequently discharge spontaneously during the night, finding their exit through the natural orifice of the antrum, when the body is in the horizontal position.[514]