Page 60 - My FlipBook

44 THE TREATMENT OF TEETH
3 2 produced bad adaptation, and a specific gravity
of 17"5.
Reducing the size of tlie plugger point by half,
produced a good—but not perfect—adaptation of
the No. 32 strips, and a specific gravity of 18*4,
Pellets cut from a loose rope of one-third of a
sheet of No 4 foil, packed and condensed with the
three sixty-fourths of an inch plugger, gave a similar
adaptation to the No. 32 strips, manipulated with a
plugger of half this size, and produced a specific
gravity of 18'1.
Pellets cut from a half-sheet roll of No. 4 foil
produced 'perfect adaptation with a one sixty-fourth
of an inch plugger. The specific gravity was not
taken in this case.
The gold in these experiments was fully annealed
on the electric annealer, with the exception of the last
€ase, in which the naked spirit-lamp flame was used.
Seven experiments were made with hand- pressure,
using various sizes of pluggers, and gold prepared
in the form of pellets and cylinders. With a
plugger-point just over one thirty-second of an inch
in diameter it was found the fillings made with
unannealed gold were better adapted than those
made with fully annealed gold and the same
plugger. The best adaptation was obtained with
small cylinders (Morgan Hastings' extra pliable