EARLY DESTRUCTION OF THE TEETH. 125 



niuch practical benefit has as yet resulted, from the 

 more minute and scientific mode of investigation 

 which the bone of the tooth has undergone, by 

 means of the microscope. It appears evident 

 enough to me that sufficient cause for the evil to 

 which the teeth are liable is to be found upon 

 the surface : there the predisposing cause of their 

 destruction clearly enough presents itself to the 

 naked eye. 



In examining the bone of the tooth through the 

 microscope, to so7iie it appears to present a tubular 

 structure, and the tubes to contain a circulating 

 fiuid, which they assume to be sufficient proof of the 

 vitality of the bone; to others the same tubular 

 structure presents itself, but to them the tubes 

 appear to be filled up with earthy matter, thus 

 putting a stop to the circulating medium. 



We are greatly indebted to the microscope for 

 many grand and useful discoveries ; but we perceive 

 that the high power of this instrument is liable 

 sometimes to present to the mind's eye appearances 

 which are not always real, but imaginary. 



We have, however, come by experience to the 

 knowledge of two important facts in connexion with 

 the character of the bone of the tooth ; the one is, 

 that its destruction takes place in the absence of 

 pain ; and the other, that the attack is always made 

 from without, and never from within. 



Much has been said and written, and various 

 representations have been given, of the bone's struc- 



