In the light of scientific investigation there can be but one method--a method based upon the recognized principle that the _filling-material_ and the _manner_ of _introducing_ it shall correspond to and be in harmony with the living, vital organism with which it comes in contact. "After excavating, the cavity is treated with absolute alcohol, as cleanliness and thorough dryness are absolutely essential. "The _tin_ is put in with steel pluggers, after the method of wedging; it must be thoroughly condensed, so as to leave a smooth surface, and enough used to come up to where the enamel and dentin join. "The effect is not produced by incorporating or interlacing the gold with the tin; we rely upon the affinity of the two metals to retain the gold; no undercuts, angles, or pits are made in the tin, dentin, or enamel. The gold, extra cohesive from No. 4 to 40, is made to adhere to the tin by simple contact, without pressure or force; the union is not mechanical. "The instruments used for filling the remainder of the cavity with gold are Shumway's ivory points, which adapt the gold nicely to the margin. "The set consists of five and were patented in 1881, and have been used by me since that time for manipulating cohesive gold. One 'point' is for proximal cavities in the anterior teeth; three 'points' of different sizes are for occlusal cavities; one 'point' for proximal cavities in bicuspids and molars and labial and buccal cavities; the sides, edges, and ends of the 'points' are used, as the purpose is simply to obtain contact. "The 'point' shown full size in Fig. 8 is of more general application than any of the others, and is used for proximal cavities in bicuspids, also labial and buccal cavities. The handle is made of ebony, and has a silver ferrule, from which the ivory extends to the end and completes the instrument. "The metal pin in the end of the handle is for picking up and carrying the gold." [Illustration: FIG. 8.] Tin has been used successfully for completely lining cavities, filling the remainder with gold; it is also useful for repairing gold fillings. Two or three thicknesses of tin foil may be pressed into a cavity with a rubber point or hard piece of spunk, allowing it to come well out to the margin; filling the rest with amalgam. "As a lining it presents to dentin an amalgam of tin and mercury which does not discolor the dentin like ordinary amalgam, and helps do away with local currents on the filling, which is one cause of amalgam shrinkage in the mouth." (Dr. S. B. Palmer.) When caries extends to the bifurcation of roots, make a mat of two or three layers of tin, place it in the bifurcation and use it as a base in filling the rest of the cavity with amalgam. Tin is second in importance in alloys for amalgam, as it increases plasticity, prevents discoloration, reduces conductivity and edge strength, retards setting, favors spheroiding, therefore should not be the controlling metal.