Abstract
A variety of factors may be mentioned as the probable causes of dental caries, complicating fearfully any discussion on the subject. The author has examined the luminescence emitted by various types of decayed teeth and tartars sticking to them under cathode rays, and found that the luminescence of the tooth crowns were much variegated.
This led the auther to infer that the special selective action for the trace metal element Bi due to the disturbed metabolism of mineral substances in the epithelial cells occasioned by the dystrophy of the individual was here the important factor, the pathogenic mechanism of dental caries due to the production of lactic acid advocated by MILLER (1890) being of a rather secondary importance.
