FORMATION AND GROWTH OF TEETH. 275 



to see the jaw of the infant with a ridge upon its 

 gums, harmless to the nipple ; and then at the 

 time when the powers of digestion vary, and be- 

 come suited for stronger food, to find sharp teeth 

 arise, a range of them having been provided, 

 which, when fully developed, are in exact accor- 

 dance with the size and form of the jaw of the 

 child? Can any one tell us how these teeth 

 should waste at an appointed time, to give place 

 to others of stronger form and of larger dimen- 

 sions conforming to the adult jaw-bone ? The 

 phosphate, carbonate, and fluate of lime, do not 

 differ in these milk teeth, or deciduous teeth, and 

 in the adult teeth ; yet, by a secret process of 

 decay, the first fall out in the period of childhood, 

 and the second last a long lifetime. 



