E;*+ - Geological Curators

In most cases two or more applications and burn-offs will be required.
Caution: any projecting corners and edges of bone may char in the flame
if not protected. This burning operation helps to dry the surface and
leaves a skin of cement that helps to hold the specimen together while it
is being extracted. Moisture will of course make the .cellulose turn
white, but its transparency can be restored in the laboratory by applying
acetone under a hea't lamp.
After being doped, the specimen is isolated by trenching and extracted
in the usual manner. If circumstances require it and the advancing tide
allows enough time, plaster-jacketing is in order. In Nova Scotia,
however, our usual practice is to omit the jacket and simply pop the bone
out in B block of matrix by insinuating an oyster-knife under it. (The
oyster-knife --in effect a thin-bladed chisel with a temper mild enough to
leave it flexible but not brittle--is such a superior collecting tool that
I'm surprised more field men don't use it. Besides being useful for
trenching in soft sandstone, it is invaluable for splitting slabs without
fracturing them.) The damp block is then wrapped tightly in paper towelling .
and cinched with sticky tape or postal rubber bands. Specimen and matrix
tend to be friable when wet but they gain strength as the package dries.
Andnow a word about plaster. Complaints are heard that the old
collector's standby, molding plaster, is becoming increasingly hard to
obtain even in cities, much more so in the boondocks. This problem seldom
arises in gypsum-rich Nova Scotia where all kinds of plaster are manufactured
locally, but still it sometimes happens that the only plaster available
is the slow-setting type used for finishing walls. Dry-gulch collectors
who find themselves in this predicament can accelerate the setting time by
adding salt to the water. In Nova Scotia, however, an unlimited supply of
pre-salted water is delivered free to our collecting sites by Davy Jones.
This obliging service compensates a little for the fact that Davy Jones has
usually stolen the best fossils, or the best parts of them, before we get
to the outcrop.
REFERENCE
Carroll, R.L., et al., 1972. Vertebrate paleontology of eastern Canada.
Field excursion A59 guidebook, XXIV International Geological Congress,
Montreal, 113 pp.
Donald Baird
Museum of Natural History
Princeton University
Princeton, New Jersey
08540 F
This article was first published in "The Chiseler" Vol. 1 No. 2, July 1978
whose Editor, Allen D. McCrady of Pittsburgh Pennsylvania, we thank for
permission to reproduce.