492 ORGANS OF DIGESTION. 



they are commonly incisors. J. Hunter saw an example of the 

 kind.* The Countess of Desmond, who lived to her hundred 

 and fortieth year, had, at this period, according to Bacon, a 

 third set of teeth.t Mentzelius narrates a similar casej in the 

 following words: having accompanied the Elector of Branden- 

 burg on a visit to Cleves, in 1666, there arrived, at the same 

 time, a man aged one hundred and twenty, who exhibited him- 

 self for money, and whom I saw at the court of the Elector. 

 His strength of voice manifested that of his breast, and he having 

 run over the gamut, was heard at more than a hundred paces 

 off. Having then opened his mouth, he showed us two rows of 

 pearly teeth, and on the subject of their beauty related ' that be- 

 ing at the Hague two years before, on the same errand which 

 brought him to Cleves, there arrived an Englishman aged one 

 hundred and twenty; that he visited the latter, and addressed 

 him in the following terms: ' We are nearly of the same age, 

 for I am only two years younger than you, and I have had the 

 greatest desire to see one older than myself, for I have felt no 

 inconvenience till lately; but during the three days that I have 

 been here, I have had severe headach and dreadful pains in the 

 jaws, which convince me that I am about to die.' ' You are 

 mistaken, my dear friend,' said he to me: 'on the contrary, 

 you are becoming younger, for you are about to teethe again 

 like an infant.' Oh !' answered I, 'I pray to God not to punish 

 me by prolonging my days.' I left him then and went to bed, 

 and immediately after felt the most excruciating pains in the 

 jaws, which were followed by the protrusion of the teeth that 

 you now see." J 



The circumstance of a third dentition, has given rise to a ques- 

 tion among physiologists, whether the germs are primarily super- 

 numerary ? or whether the gums have within themselves organs 

 capable of forming and of producing new teeth? 



When such teeth come out in a straggling manner, they hurt 

 the opposite jaw, and require to be extracted. 



In old persons who have lost all their teeth, there is a carti- 

 laginous hardening of the gum, as in infancy, whereby they still 

 retain some power of mastication. 



When the body of the tooth has been worn away, nature pre- 

 vents the exposure of its cavity by the deposite of new matter, 



* Loc. cit. p. 85. t Hist, vit et mort. Col. 536. 



t Serres, loc. cit. p. 40. 



