There has been, without doubt, a gradual change in practice for the past fifteen years, brought about by sad experiences and the better knowledge of the tissues involved; also by the improved educational condition of the profession as a whole. Dr. Black, in the _American System of Dentistry_, on "The Pathology of the Dental Pulp," has given us, as far as I am able to judge, by far the best and most instructive contribution upon this subject. He concludes his sixty pages of valuable observations as follows: "PATHOLOGY OF THE DENTAL PULP—GENERAL CONSIDERATIONS." "In the foregoing pages I have frequently alluded to the fact—which is apparent in a very large proportion of my microscopic preparations—that any of the secondary calcific formations within the pulp of the tooth, result in exhaustion and final death of the pulp. This fact is so prominent that it seems to me that it cannot well be overlooked; and yet, in the capping of exposed pulps, it seems to have been the thought of the profession that to be able to obtain a secondary deposit under such circumstances was to insure the permanence of the health of the pulp. This was my own thought some years ago, but further clinical experience, combined with closer microscopical study of the subject has convinced me that this is a mistake. Secondary deposits may, and do, insure temporary quiet, but so far from insuring health are they, that, as a matter of fact, they bring about the very conditions that we most wish to avoid—the degeneration and final destruction of the pulp. "In a large majority of cases, however, this result is brought about very slowly, and thus has escaped the notice of most observers; for if an exposed pulp is capped and the cavity filled, and the case seems to do well for a year or two, it is regarded as a success, and is lost sight of. When this returns some years later with a dead pulp, it is treated as one of the great mass of such cases that are constantly presenting themselves, and probably no note was made of the fact that it was capped at a certain time, and was one of the many successful cases. "Very many cases of capping pass on for years without any deposit whatever, and seem to remain in a perfectly healthy condition. This we must regard as the most desirable result that can be obtained. Enough of these cases have been noted to demonstrate the possibility of rendering the conditions so nearly normal that no disturbance of the functions of the organ occurs."