Vlll INTRODUCTION. 



and most other teeth, offer a very different character, and one 

 which has led to many approximations and allusions to the true 

 structure of dentine, in the works of anatomists who have recorded 

 their own original observations. 



Whoever attentively observes a polished section or a fractured 

 surface of a human tooth may learn, even with the naked eye, that 

 the silky and iridescent lustre reflected from it in certain directions 

 is due to the presence of a tine fibrous structure. 



Malpighi, in whose works may be detected the germs of many 

 important anatomical truths that have subsequently been matured 

 and established, says that the teeth consist of two parts, of which 

 the internal bony layers (dentine) seem to be composed of fibrous, 

 and as it were, tendinous capillaments reticularly interwoven. (1) 



Retzius cites many recent authors, as Soemmering, Schreger(2) and 

 Weber, (3) who mention the silky glistening lustre of the dentine ; and 

 Frederick Cuvier in the preliminary discourse of his admirable work 

 the * Dents des Mammiferes,' observes : *' Les dents de I'homme, de 

 singes, de carnassiers ont un ivoire d'apparence soyeuse, qui semble 

 forme de fibres," p. xxvii. These inteUigible hints of the true struc- 

 ture of the dentine, which the foregoing observers received from a 

 superficial but unprejudiced inspection, failed, however, to incite them 

 to a closer interrogation of Nature. 



One of her more persevering investigators had, nevertheless, long 

 before obtained a true and definite answer to his more direct in- 

 quiries. Leeuwenhoek, having applied his microscopical observations 



(1) " Duplici excitantur parte, quarum interior ossea lamella fibrosis et quasi tendinosi 

 capillamentis in naturam implicetis constat."— Anatome Plantarum, Lugd. Batav. 1687, p. 37. 



(2) Isenflamm und Rosenmiillers Beitragen zur Zergliederungskunst, band i, p. 3, (1800). 



(3) See his Edition of " Hildebrand's Handbuch der Anatomie," band i, p. 206. 



