I BELIEVE the experiment of putting 1 part per million of flourine in the municipal water supplies of various cities which is now in progress in order to prevent tooth decay, is being prematurely tried. Fluorine as related to tooth decay has not had nearly the exhaustive study dental fluorosis has had. There is no quarrel as to the validity of both conditions, but there has not been established by all investigators the amount of fluorine which is nontoxic and also effective in prevention of tooth decay.
The United States Public Health Service, which is fostering this experiment, stated that 1 part per million (p. p. m.) is not toxic, basing this observation, for the most part, on the work of Dean.1 In their investigation on the relation between fluorine and dental caries a simultaneous study was not made regarding dental fluorosis.2
There are several areas in the