Chemistry Reference
In-Depth Information
approximately the fifth century B.C.E.), for example, revealed that it could
have been made in Italy but gave no hint as to its age. Although thermolu-
minescence measurements indicated that all the pieces that made up the
statue were of the same age (ca. 2400 years old), each piece had formerly
been part of different statues, and the “reassembled, pastiche statue” was a
modern forgery.
18.2.
SOME AUTHENTICATION STUDIES
The Piltdown Man
An illuminating example of a longstanding authentication controversy
settled by the use of scientific methods is the by now historical case of the
Piltdown Man (Spencer 1990; Weiner 1981). Fragments of a human braincase
and a jawbone, together with teeth of various mammals and a tool carved
from an elephant tusk, were reportedly found at Piltdown in Sussex,
England, in 1912; a thorough anthropological examination, it was claimed,
revealed that the human bones belonged to a 500,000-year old, hitherto
unknown fossil ancestor of human beings named
Evanthropus dawsoni
or
Piltdown Man.
Some anthropologists at the time could not accept, however, that both
the braincase and the jawbone belonged to a single individual, since the
jawbone appeared to belong to an ape while the braincase was more human.
The controversy that hence arose occupied the scientific world for over 45
years.
Fluorine analysis of the Piltdown bones made in 1949, showed that
neither the braincase bones nor the jawbone contained more than minute
traces of fluorine, whereas other fossil bones from the same gravel bed con-
tained a great deal of it. This reduced the possible age of the skull to below
50,000 years. A more refined analytical technique revealed, however, that the
amount of fluorine in the braincase was sufficient to account for its being
ancient, but that the jawbone and teeth contained no more fluorine than did
modern bones (Oakley and Hoskins 1950). Other chemical analyses con-
firmed that the jawbone and teeth contained the same amount of nitrogen
as did modern species. The braincase, on the other hand, contained much
less. Used as a crosscheck against the fluorine tests, this provided quite
conclusive evidence that the jawbone was modern; additional tests
that followed, confirmed that the jawbone really was modern. Electron
microscopy revealed preserved fibers of organic tissues in the jawbone, in
contrast to the braincase, where there were no traces of such fibers. So the
jawbone was exposed as a bogus fossil of undoubted modern origin
