The following facts were learned from Dr. Corydon Palmer: E. E. Smith, who had been a student of John and William Birkey, in Philadelphia, came to Warren, Ohio, in 1839, and among other things made the first gold plate in that part of the country. In operating on the anterior teeth, he first passed a separating file between them, excavated the cavity, and prepared the foil, _tin_ or gold, in tapes which were cut transversely, every eighth of an inch, about three-quarters of the way across. Fig. 1 shows the size of tape and the manner of cutting. With an instrument (Fig. 2) he drew the foil in from the labial surface, using such portion of the tape as desired. The instrument from which the illustration was made was furnished by Dr. Palmer, and is shown full size. Instruments for use on posterior teeth were short and strong, with as few curves as possible; no right and left cutters or pluggers were used, and none of the latter were serrated, but had straight, tapering round points, flat on the ends, and of suitable size to fill a good portion of the cavity. He used what was termed Abbey's chemically pure tin foil, forcing it in hard, layer upon layer,--as he expressed it, "smacked it up." In this manner he made tin fillings that lasted more than thirty years. In 1839 Dr. Corydon Palmer filled teeth with tin foil, also lined cavities with gold and filled the remainder with tin. In the same year he filled crown (occlusal) cavities one-half full with tin and the other half with gold, allowing both metals to come to the surface, on the same plan that many proximal cavities are now filled. (See Fig. 3, showing about one-half of the cavity nearly completed with tin cylinders. The same plan was followed when strips, or ropes, were used.) "I filled cavities about two-thirds full with tin, and finished with gold." (S. S. Stringfellow, _American Journal of Dental Science_, 1839.) "Tin foil is greatly used by some American dentists, but it is not much better than lead leaf." ("Surgical, Operative, and Mechanical Dentistry," L. Charles De Londe, London, 1840.) [Illustration: FIG. 3.] "In 1841 there were about twelve hundred dentists in the United States, many of whom were using tin, and there are circumstances under which it may be used not only with impunity, but advantage, but it is liable to change." (Harris.) "I put in tin fillings, and at the end of thirty years they were badly worn, but there was no decay around the margins." (Dr. Neall, 1843.) In 1843 Dr. Amos Westcott, of Syracuse, N. Y., filled the base of large cavities with tin, completing the operation with gold.