14 REPORT — 1841. 



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 two papers readbefore the Medical Section at 



..^Birmingham, furnished by himself to the Editor of the Athenceum Journal, 



and printed in No. 620, page 707. Sept. \Uh., 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 sei'ies 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. Neis- 

 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] f exist on the 

 formative surface of the pulp. Mr. Nasmyth [now]f next* proceeded to the 

 [most diflScult department of the subject — to that which former inquirers have 

 either evaded or treated very incompletely, viz. the]f 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 stiuctuie [mayjf a'iVt* 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. 



f The words in brackets are in the original manuscript, but are not in the Athenaeum. 



