Case 4, is that of a central incisor, pulp destroyed, canal filled, in which a Howe screw-post was used as an anchor to secure a large contour filling. Some time after, the tooth began to show a decidedly green discoloration, near the neck, which gradually extended throughout the crown. The filling was removed and replaced, however, using a screw of silver and platinum instead. I have here two specimens of roots in which the Howe post has been used, and have seen two other cases in the mouth, the same green stain appearing in all. When the Howe post was put upon the market by the White Manufacturing Company, their agents refused to tell of what metal they were made, but gave the impression that they were some form of platinum and iridium alloy. They proved, however, to have been made of chrome steel. Besides the disagreeable discoloration of all these roots, I am inclined to the believe that the chrome salt formed, acts as a constant irritant to the peridental or dental membrane, and will result ultimately in the loss of the tooth. Case 5:—In this case the left superior second bicuspid was devitalized and became discolored. The gentleman who was the lady's dentist at the time, desiring to improve the appearance of the tooth, removed the dentine extensively on the labial surface, and proceeded to fill with gold. When the tooth came into my hands for treatment, I found the part of the filling against the lingual wall well condensed, but that against the frail labial wall quite soft, and this portion of the filling had leaked, and the tooth was again discolored, showing that in order to avoid undue pressure on the thin enamel wall, insufficient force had been applied to condense the gold. Would it not have been better in this case, and in fact in all similar cases, to have sacrificed somewhat the appearance of the tooth and made a more permanent filling by the removal of all that portion of the enamel which was liable to fracture. Case 6, is one of those mistakes in diagnosis which are liable to occur in almost any practice. Miss E. presented herself with every appearance of an abscessed right superior second molar, a large sac protruding into the mouth, opposite the palatine root. The tooth was so extremely loose and so sore that the patient would not allow it to be opened. The abscess sac was opened and syringed out, and two days later the soreness of the tooth had sufficiently subsided to permit the removal of the filling. Drilling toward the pulp chamber, a short distance, developed the fact that the tooth contained a living nerve. The result of this case showed that the abscess was caused by the lodgement of a fragment of a wooden toothpick between the first and second molar.