Treatise on the natural history and diseases of the human teeth : explaining their structure, use, formation, growth, and diseases, in two parts / by John Hunter ; with notes by Thomas Bell.
- John Hunter
- Date:
- 1839
Licence: Public Domain Mark
Credit: Treatise on the natural history and diseases of the human teeth : explaining their structure, use, formation, growth, and diseases, in two parts / by John Hunter ; with notes by Thomas Bell. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![so many points of the brim of the cavity, which meet in the centre and divide the whole into three openings;* and from these are formed the three fangs.f We often find the fangs forked at their points, especially in the bicuspides. In this case the sides of the fang as it grows come close together in the middle, making a longitudinal groove on the outside; and this union of the opposite sides divides the mouth of the growing fang into two orifices, from which the two points are formed. By the observations which I have made in unravelling the texture of the teeth when softened by an acid, and from observing the dis- position of the red parts in the tooth of growing animals interruptedly fed with madder, I find that the bony part of a tooth is formed of lamellae placed one within another. The outer lamella is the first formed and is the shortest; the more internal lamellae lengthen gra- dually towards the fang, by which means, in proportion as the tooth <rrows longer, its cavity grows smaller, and its sides grow thicker. J ° How the earthy and animal substance of the tooth is deposited on the surface of the pulp is not perhaps to be explained.^ Of the Formation of the Enamel. In speaking of the enamel we postponed treating of its formation till it could be more clearly understood; and now we shall previously describe some parts which we apprehend to be subservient to its formation, much in the same manner as the pulp is to the body ot the tooth. . . From its situation and from the manner in which the teeth grow, one would imagine that the enamel is first formed ; but the bony part begins first, and very soon after the enamel is formed upon it. There is another pulpy substance opposite to that which we have described: it adheres to the inside of the capsule, where the gum is ioined to it, and its opposite surface lies in contact with the basis Of the above-described pulp, and afterwards with the new-formed basis of the tooth. Whatever eminences or cavities the one has, the other has the same, but reversed, so that they are moulded exactly to each other. In the incisores it lies in contact, not with the sharper cutting edge of the pulp or tooth, but against the hollowed inside of the tooth; and in the molares it is placed directly against their base, like a tooth of the opposite jaw. It is thinner than the other pulp, and decreases in proportion as the teeth advance. It does not seem to be very vascular. The best time for examining it is in a foetus of seven or eight months old. ' In the graminivorous animal, such as the horse, cow, &c, whose teeth have the enamel intermixed with the bony part,|| and whose teeth, when forming, have as many interstices as there are con- *PI.V. f. 13, F, G. |P]. V. f. 13, H, I, K. % PI. V. f. 7, 8. § This is explained in the note to the preceding section. II PI. III. f. 20, 21. 6](https://iiif.wellcomecollection.org/image/b21131612_0045.jp2/full/800%2C/0/default.jpg)
