Volume 1

Descriptive catalogue of the preparations in the museum of St. Thomas's Hospital.

Date:
1847-59
Catalogue details

Licence: Public Domain Mark

Credit: Descriptive catalogue of the preparations in the museum of St. Thomas's Hospital. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    tion seen very distinctly in some parts of the section. Each prism is observed to be marked by delicate transverse lines, producing an appearance characteristic of the enamel. The dentine or ivory contains a vast number of wavy tubuli which are very conspicuous; they originate from the surface of the pulp cavity, then pass outwards forming several curves ( primary curvatures, Owen) ; towards the point of the fang, with a sufficient power, many of these tubuli may be seen cut across, some directly in the transverse direction, and others obliquely. They divide and subdivide sometimes dichoto- mously, at other times irregularly. In some places, faint curved lines may be seen crossing the course of the tubuli; these are the secondary curvatures of Professor Owen. The largest of the dentinal tubuli have only a diameter of Tsio 0 inch, so that it is impossible for blood vessels to enter them, but they can and do receive the plasma of the blood. The intertubular matter forminor the substance of the dentine has in the section a granular appearance. The cement, coating the exterior of the fang is best examined towards the extremity: it presents the character of time bone, and is especially distinguished by the lacunae and canaliculi; but no Haversian canals exist in the cement of human teeth, although they are found in that of some other animals. The general position and extent of the three component struc- tures are best imderstood by examining the section with the naked eye. 42. Transverse section of a human molar tooth, showing tlie fibres of the enamel and its junction with the dentine. In the centre of the tooth the tubuli of the ivory are very distinctly seen, divided transversely; their proper walls, and their relation to the intertubular substance are also here well shown ; proceeding outwardly from the centre, tlie tubuli .are cut more and more obliquely, an appearance best observed by altering the focus ; and wliere approacliing the enamel, the tubes have been divided horizontally. 43. Vertical section of a portion of Elephant's tooth, showing tlie position and structure of the enamel, dentine, and cement.