T. C. WHITE ON THE SO-CALLED " NERVE" OF THE TOOTH. 11 



tooth and impurities of various kinds cling most tenaciously to tlie 

 odontoblasts, and not only obscure the view of the delicate details, 

 but look unpleasant and slovenly. The plan found to answer best is to 

 file a longitudinal groove round the tooth ; then, having washed away 

 all the debris very thoroughly, split the tooth with a pair of wire 

 nippers, when it will come clearly in two and expose the pulp for 

 its whole length, when it may be withdrawn by seizing it at its 

 smallest part and tearing it out of the cavity. This will draw out 

 not only the odontoblasts but some of the dentinal fibres attached 

 to them. Another very good plan for observing the relation of the 

 pulp to the dentine is to soak the tooth for a few weeks in the 

 carmine staining fluid, which becomes sucked up through the 

 foramen of the fang, and being absorbed by the pulp, colours it 

 completely. The tooth may then be decalcified by immersion in 

 ordinary hydrochloric acid, which removes the lime but does not 

 hurt the soft tissues. At the end of a fortnight the tooth may be 

 cut in thin slices, when the pulp will be cut with the decalcified 

 osseous tissue, and the relation will be well shown. I have thus, 

 in these few brief remarks, which fail to do justice to my subject, 

 endeavoured to show you that that which is generally called the nerve 

 of a tooth is in reality a mass of areolar or connective tissue, through 

 which ramify the nerve, vein, and artery destined for the life of a 

 tooth, that its function originally was the formation and building 

 up of the dentine, that its powers in adult life remain dormant, but 

 capable of being aroused under the action of a stimulating influence 

 to develope dentine again, and that it performs an important part 

 in ministering to the vitality of a tooth, as well as constituting 

 a tooth a very delicate sensory organ. These few remarks, there- 

 fore, will, I hope, have the effect of inducing others to take up the 

 comparative histology of the pulp, and lead them to investigate its 

 tissues in some of the lower animals, both in their foetal condition 

 and at maturity, and I can promise them a rich reward in return 

 for their labours in new fields of observation open, and fresh revela- 

 tions of the skill of the Great Architect of All. 



