compressing as above till it le f. By this method there is danger of fracturing the tooth, breaking down the wall of the cavity, where the filling is terminated. Another method is to fill up the cavity principally with blocks, and to put in the last part of the filling in the strip, filled in from the bottom to the orifice. The objection to this method is, that unless adhesive foil is employed, the portion inserted in the strip is liable to be displaced, and in this way the whole filling become destroyed.

Another method of arranging this kind of filling, particularly when the bottom of the cavity is irregular, is to make a large, flat pellet, condense it firmly to the bottom, and set the blocks upon this for a foundation. By this method there is a more perfect adaptation of the gold to the bottom of the cavity, than by placing the ends of the blocks down upon an uneven surface. After the gold is all introduced, a small pointed plugger must be passed over the entire Purface, to consolidate the protruding portions. These protruding portions should be sufficient to make the si face, after being condensed, perfectly flush with the border of the cavity, for a depression here is fital to a complete finish, except by the addition of cohesive gold. After the condensation with the finely serrated points, then the blunt, smooth, polished, points should be used with the mallet all over the sun face of the filling, then the files, burs, stones, etc.,

of the various grades should be used to complete the finish.

Dr. Badger described a method of filling a small cavity on the posterior proximate portion of a second molar, the third molar gone. The cavity is formed with a bur drill. A cylinder is then formed in the usual manner, and forced through a series of holes in a drawplate, down to the size of the bur with which the cavity is prepared. The block is thus rendered quite dense. The cavity is then dried, and the block forced into it, which it exactly fits, protruding a little from the orifice. This block is pierced in the centre with a sharp instrument, and a small dense roll forced into it; all is then condensed, and finished in the usual manner.

Pellets.-Pellets made by rolling fragments or pieces of foil between the thumb and fingers are used by some operators, and with them they profess to make as good filling as by any other method. They are made of various sizes, and packed into the cavity with sharp-pointed or serrate-pointed instruments. The pieces may thus be very solidly worked together, and a good filling made, provided the pellets are not too large; they should be small enough to permit the point or points to work through them into the preceding portions. Some operators use pellets and crystal gold together. This may do very well if the cohesive property of the gold is employed; but in that

case, either form of the material would answer alone. There cannot be as much gold put in by pellets as by blocks or cylinders well adjusted.

Cohesive Foil.-By this is understood that condition of gold foil in which the leaves unite readily and firmly together. This property of cohesion is possessed in the greatest degree by properly manufactured foil, immediately after annealing. Not that annealing imparts any new property to the gold, but it removes obstacles to the manifestation of a principle possessed by all gold under favorable circumstances. It is now about twenty-five years since this property was first employed in gold foil for filling teeth. To Dr. R. Arthur is due the credit of first directing the attention of the profession to it, as being available for filling teeth. He not only did this, but he entered most fully into the details of the manipulations, instruments, etc., pertaining to this mode of operation. Almost all recently-prepared gold foil possesses this property to a greater or less degree; there are methods of preparing it, however, by which it possesses it more fully; all recently annealed foil is cohesive. If the foil is in this condition when we wish to use it, nothing further is required in the way of preparation. But if it is not cohesive,―as almost all foil is not, especially if it has been much exposed to the influence of the atmosphere, it will require to be made so by some pro

cess.

There are two methods, either of which will

well accomplish the object.

The one most frequently employed is that of heating the gold, either in the sheet, in the roll, or in fragments, over the flame of a spirit-lamp, almost or quite to a red heat; if in the sheet, it should be laid. upon a piece of wire gauze, and passed over the flame of the lamp for a moment or two; if in the roll, it may be taken in the centre with fine pliers and passed rapidly through the flame. But if the gold is in the form of pellets, blocks, or cylinders, or small pieces of any shape, it may be taken up with the pliers and passed rapidly through the flame of a spirit-lamp, till all foreign substance is burned or driven from it. Or it may be placed on a sheet of mica, which is adjusted over a flame, and then brought to a proper temperature.

There are different methods of using gold in this condition; but in general the cavity should be formed about as for the other methods of filling, except that at some point or points the cavity should be formed so as to retain firmly the first portion of gold introduced; such anchorage should be located with reference to convenience, and the strength of the tooth. The first portion of gold should be a little pellet; this, forced into these retaining spaces, serves as a foundation for the remaining portion of the filling. Dr. Arthur's method is, then to tear off fragments

from the sheet, and pass it into the cavity without folding, and condense it with an instrument of finely serrated point, so that it not only unites by cohesion, but is worked into the surface of the preceding portion of gold; and in this manner portion after portion is introduced and condensed, until the cavity is full. The filling may be commenced in any part of the cavity that is most convenient; in many, as in crown cavities of the molars, at the bottom, and filled to the orifice. In putting in the gold, it should during its introduction, be kept fuller about the walls of the cavity than in the centre; by this means the adaptation will be most perfect to the walls, and there will be no liability of clogging in the centre. The gold may thus be built up to any desired extent if the filling is kept dry; moisture is fatal to its cohesion.

Others use the cohesive gold in a different manner. To Dr. Blakesley belongs the honor of first detailing the following plan: The sheet of gold may be folded or not, at the pleasure of the operator, and then each sheet cut into from two to six strips, and each of these formed into a loose roll between the thumb and fingers. These should now be passed through the flame, as already described, then cut into little blocks or pellets of various sizes; these to be regulated by the size of the roll and the cavity to be filled. For the introduction of the gold thus pre