cohesive gold
filling, while such a surface is impossible with non-cohesive gold. In
cavities which extend so far beyond the margin of the gum that it is
impossible to adjust the rubber-dam, I prepare the cavity as usual, then
adjust a matrix, disinfect, dry, and fill one-third full with tin and
gold, then remove the matrix, apply the rubber, place matrix again in
position, and complete the filling by adding a little tin and gold, then
pure gold." (Dr. W. A. Spring, _Dental Review_, February, 1896.)

Dr. T. D. Shumway says, "To have a scientific method of treatment, there
certainly must be a recognition of what is known of the nature of
tooth-structure. The method adopted more than a quarter of a century
ago, and which is at present employed, does not accord with the
teachings of the physiologist and microscopist; it is in direct
opposition to natural law. Each new discovery in the minute structure of
the teeth makes this more plain; pounding the teeth with a mallet cannot
be defended on scientific grounds. That it has not resulted more
disastrously is due to the wonderful recuperative energy of nature to
repair injury. No one would think of attempting to arrest and prevent
disintegration in any other vital organ by abrasion. Why, then, in
operation on the teeth, should we reverse the plain, simple teaching of
nature? Placing cohesive gold against the dentinal walls by pounding it
to heal a lesion is opposed to natural law. Cohesive gold will not be
mastered by force; if compelled to yield by superior strength, it seeks
a way to release itself; it is easily coaxed, but not easily driven.
Cohesive gold will unite with tin at an insensible distance just as
cohesive gold unites with itself; this union takes place without force
or pressure. Exactly what takes place when gold and tin are brought in
contact in the way described we do not know; we can only say that there
appears to be a perfect union. When cohesive gold was introduced to the
profession, while it was softer than non-cohesive foil, it was found to
resist under manipulation. This resistance is in accordance with the
well-known law that all crystalline bodies, when unobstructed, assume a
definite form. With gold the tendency is to a spherical form. The
process of crystallization is always from within outward. The mallet was
introduced to overcome the resistance caused by the development of the
cohesive property. Pounding gold with a mallet only increases its
crys