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XXIV. On the Presence of Fibrils of Soft Tissue in the Dentinal Tubes. 
By John Tomes, F.R.S., Surgeon-Dentist to the Middlesex Hospital. 
Received February 21, — Read March 13, 1856. 
The dental tissues, as parts of the human system, have received their full share of 
attention from anatomists. Papers have from time to time appeared upon this sub- 
ject, each observer confirming or correcting the views of his predecessor, or adding- 
new facts to those already recorded, until this field of investigation seemed fairly 
exhausted, at all events of new matter. 
Histologists, I think, now agree that dentine is made up of series of tubes, which 
radiate from one or more cavities, situated within the interior of the tooth. In their 
way outwards the tubes branch freely, and connect themselves through their branches 
with each other; thereby establishing a network of communications throughout the 
whole substance of the dentine. The tubes on the one hand, after running their 
course, become lost in the anastomosing branches near the outer surface of what has 
been termed a dentinal system, on the other, terminate by open mouths on the inner 
surface of the system*, or pulp-cavity. This cavity being occupied by an organ rich 
in blood-vessels, has led to the opinion generally entertained, that the tubes are canals 
for the conveyance of nutritive fluid. 
M. Kolliker'I' states, “During life the (dentinal) canals contain a clear fluid, and 
cannot therefore be readily detected in recent preparations.” 
In sections which have been dried, the tubes become very distinct, and we may 
sometimes, on adding a coloured fluid to the preparation when under the microscope, 
observe the tubes becoming gradually filled. 
The foregoing conditions of the dentinal tubes are so easily demonstrated, and 
appeared to indicate so satisfactorily the offices of these canals, that the subject was 
regarded as one which had been fully investigated. There are, however, certain phy- 
siological conditions observable in teeth, when forming part of the living body, which 
the recorded knowledge of the histological characters of dentine fails to explain. 
If, for instance, a portion of enamel be accidentally broken from the surface of a 
tooth, so that the dentine becomes exposed, the surface of the latter will be highly 
sensitive to any variation of temperature from that of the mouth, or to the contact of 
* “On the Structure of the Dental Tissue of the Order Rodentia,” by John Tomes, Philosophical Transac- 
tions, Part 2, 1850. 
t Manual of Human Histology, by A. Kolliker. Translated and edited by George Busk, F.R.S., and 
Thomas Huxley, F.R.S. Vol. ii. page 41. 
3 Y 
MDCCCLVI. 
