4'42 TRANSACTIOXS OF THE AMERICAN INSTITUTE. 



is the result, which maj be placed in the tooth, and the moment 

 moisture comes in contact with it hardens, and immediately 

 becomes part and parcel of the tooth j it is white, pure, perma- 

 nent, and precisely like the tooth, and if the nerve is exposed it 

 allays its susceptibility to pain. 



The teeth are integral and component living portions of the 

 human system, as much so as the heart. They are nourished by 

 a circulation of blood through them. The cause of decay in 

 teeth is the gradual wearing off of the enamel and grinding sur- 

 faces, which, without pain, become so short in time that the 

 alveolar processes discharge their duties. Animal food and 

 warm drinks are probably detrimental to teeth, from the fact that 

 the North American Indian who subsists chiefly on corn, vegeta- 

 ble diet and cold meats, has fine teeth. Southern negroes, whose 

 diet is chiefly vegetable, are remarkable for the regularity and 

 whiteness of their teeth. The same fact is observable among 

 cattle fed on natural and unnatural food. 



Before I left the country, I examined the teeth of my cows and 

 oxen, fed on natural food. They were covered with enamel, free 

 from tartar, healthy, firm, the alveolar processes sound, and breath 

 sweet. On examining, a short time since, the teeth of cows fed 

 on hot swill from a distillery, J found them broken off; the 

 enamel entirely gone, and black spots on the sides of the stumps 

 left, ulcers at the roots, and the interstices between the teeth 

 covered with tartar, filled with living microscopic matter. 



During childhood infants should be confined to milk, as is indi- 

 cated by the fact that they have no teeth before they are six or 

 seven months old ; still I have seen them fed meat long before 

 that period. At two years old their first set is complete, con- 

 sisting of ten in each jaw ; at eight years old these are shed and 

 permanent teeth appear. At the age of twenty the wisdom teeth 

 generally appear. At the age of forty half of them at least have 

 disappeared. Still this need not alarm those who have been so 

 unfortunate, as dentistry has arrived at such perfection that the 

 mouth ;may be fitted with a new set, scarcely to be distinguished 

 from those formed by nature. A few years since this feat could 

 not be accomplished, except with teeth made of bone or ivory, 

 which were acted upon by the gastric juice, changed color, and 

 rendered the breath disagreeable ; now, perfectly incorruptible 

 minerals are used, which bid defiance to all chemical agents, and 

 may be considered a vast improvement in dentistry. 



