This work was begun ten years since, and in its substantial features was ready for the press some time ago; publication was deferred in order to make the whole more scientifically complete, but I realize that it is useless to wait until a reversal of opinion on some topics is rendered impossible. In the mean time, I have revised and rewritten the whole, and have endeavored to make it the embodiment of the latest knowledge upon the different subjects treated.<br><br>Since the act was passed by the New York Legislature in 1868 creating a Board of Censors, I have been the member of that Board upon whom devolved the duty of examining dentists upon these branches.