Volume 1

[Report of the Council respecting the publication of A. Nasmyth's papers on the structure of the teeth].

  • British Association for the Advancement of Science. Meeting
Date:
[1841]
Catalogue details

Licence: Public Domain Mark

Credit: [Report of the Council respecting the publication of A. Nasmyth's papers on the structure of the teeth]. Source: Wellcome Collection.

    14/24 (page 14)
    Sections, before which their papers have been read,—the repetition of similar cases in future will be effectually prevented. SUBJOINED DOCUMENTS. (A.)—Reports of Mr. Nasmyth’s tiro papers read before the Medical Section at Birmingham, furnished by himself to the Editor of the Athenceum Journal, and printed in No. 620, page 707. Sept. 14 th, 1839. Reprinted from the Original Manuscripts, and showing the differences between the Manuscripts and the Reports as they appeared in the Athenceum. Mr. Nasmyth read a paper “ On the Microscopic Structure of the Teeth,” in which he treated also of the covering of the enamel and of the organization of the pulp. He first stated that his researches had led him to a conviction contrary to that of Retzius, Purkinje, and Frankel, for he had found that the enamel in all cases possesses a distinct envelope or coating. On the incisor of the calf, and on several other simple teeth, he had also traced in it the cor¬ puscles of Purkinje, analogous to those found in bone**. With respect to the microscopic structure of the teeth, Mr. Nasmyth treated principally of the in- terfibrous substance, which he said was not “ structureless,” as has been erroneously stated, but decidedly cellular. The fibres themselves he described as presenting an interrupted or baccated appearance, as if made up of com¬ partments, which differ in size and relative position in various series of animals. He detailed their peculiarities in the human subject, in some species of the monkey tribe, and in the oran outan. After the earthy matter of teeth has been removed by acid, the animal residue, he stated, consists of solid fibres, and if the decomposition be allowed to continue, these fibres present a pecu¬ liar baccated appearance. The general appearance of the fibres treated by acid is similar to that of the fibres of cellular tissue generally, and the diameter of each corresponds exactly to the calibre of the dental tube, as described by Retzius, and which, according to that writer, is pervious, although at the same time he says that it is always more or less filled with contents of an earthy nature. With regard to the internal structure of the pulp, Mr. Nas¬ myth stated that the number of minute cells presenting themselves in its in¬ terior, in a vesicular form, is very remarkable. They vary in size from the ten-thousandth to one-eighth of an inch in diameter, and are evidently dis¬ posed in layers. The parenchyma of macerated pulp is found to be traversed by vessels, and to be interspersed with granules. The arrangement of these cells or vessels, Mr. Nasmyth thinks, may account for the shrinking or nearly total disappearance of the pulp which he has frequently observed : their use in the ceconomy of the part he has not yet ascertained. They are evidently filled either with air or fluid. He finds that they [constantly]! exist on the formative surface of the pulp. Mr. Nasmyth [now]f next* proceeded to the [most difficult department of the subject—to that which former inquirers have . either evaded or treated very incompletely, viz. the] j* nature of the process by which the ivory is developed. The formative surface of the pulp, which is in apposition to the ivory, and by which the latter is produced, he described as presenting a general cellular arrangement, which he denominated reticular, re¬ sembling a series of skeletons of a desiccated leaf. This reticularity is found to have peculiar diversities in different classes of animals. Mr. Nasmyth has ** A full description of this structure [may]f will* be found in a paper by Mr. Nasmyth, in the forthcoming volume of the Transactions of the Medico-Chirurgical Society, accompanied by drawings. * The words in italics are in the Athenaeum, but are not in the original manuscript,