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Jefferson’s Old Bones

Did the so-called father of American vertebrate paleontology believe in fossils?

Keith Thomson

Jefferson and “Fossils”

2011-05MargThomsonFC.jpgClick to Enlarge ImageIn Jefferson’s day, the word “fossil” was undergoing a change of meaning. Prior to the mid-18th century, “fossil” (from its Latin root, fossere, to dig) referred to anything dug up out of the ground. Thus coal, diamonds, metal ores, asphalt and the remains of once-living creatures were all called fossils. Then in works such as John Woodward’s Fossils of all Kinds, Digested into a Method Suitable to their Mutual Relation and Affinity (1728) two different categories came to be distinguished: native fossils (minerals and metals) and extraneous fossils. The latter was restricted to the remains of once-living creatures, petrified and preserved in the rocks. Eventually the various elements of native fossils all found their own separate names and the term extraneous fossils (and sometimes adventitious fossils), was reduced simply to “fossils,” remained for the organic remains. From then, it was used both as a noun and an adjective. Thus in 1758, physician John Fothergill reported on “the fossile bones of an Allegator” from Whitby in Yorkshire, England, and anatomist William Hunter, writing about remains from Big Bone Lick in America in 1768, called them “fossil tusks.” Botanist Peter Collinson the same year referred to “very large Fossil Teeth” from the same source.

It is important to note, however, that at first the definition of something as a fossil did not necessarily imply great age; the whole Earth, in conventional thinking, was only 6,000 years old. But, in that context, something 5,000 years old was ancient indeed. This still left the problem of discovering how petrification occurred and how fossils were formed—how “the stoney Atoms have intruded themselves into all parts alike,” as Robert Plot put it in his 1677 publication Natural History of Oxford-shire.

In America the transition to the new set of meanings was patchy. In 1771 the American Philosophical Society proposed the creation of a new museum containing “all Specimens of Natural Productions, whether of the ANIMAL, VEGETABLE or FOSSIL Kingdoms.” A decade later, philosopher Pierre Eugene du Simitière advertised his “American Museum” in Philadelphia as including “Artificial Curiosities” (such as portraits and machines) and “Natural Curiosities.” The latter included “Marine Productions” (fishes and the like), “Land Productions” (birds and insects, for example), “Fossils” (used in the old sense of minerals and salts) and “Petrifications.” This last category included both what we now call fossils (such as bones, shells, teeth and corals) as well as a number of inorganic categories such as “fossil substances produced by the eruptions of Volcanos.” As late as 1792, when painter and naturalist Charles Willson Peale proposed his new museum for Philadelphia, he wrote that it would include “the fossil kingdom, comprehending the earths, minerals, and other fossil matters, which include petrefections.” All three projects set a line between objects that belonged to living organisms and those that were petrified.

An obvious logical difficulty created by such classifications was that an object such as a mastodon femur could be classed either as a bone or a fossil, but it could not be both. In this situation, anything that recognizably belonged to a vertebrate skeleton, even if petrified, was preferentially referred to as a “bone” or “tooth.”

A modern usage of the word fossil appeared in the minutes of the American Philosophical Society in 1784, when a collection of Big Bone Lick fossils collected by a Major Craig was described as “petrified bones.” The 1799 volume of the American Philosophical Society Transactions, which included Jefferson’s Megalonyx paper, also had a contribution from a land speculator, Judge George Turner, in which bones from Big Bone Lick were termed “extraneous fossils.” In a 1796 letter to his cousin Philip Turpin—a farmer whose land became an archeological site—Jefferson himself referred to an unspecified “petrified Bone in my possession” (evidently not part of his Megalonyx suite). Several of Jefferson’s correspondents in the 1780s and 1790s used the word fossil in its current sense. He was also familiar with the fossil shells (possibly Silurian brachiopods) that could be found in the Blue Ridge Mountains of Virginia and freely referred to them as petrified but, again, not as fossils.

Jefferson’s consistent failure to use the word in his more formal writings almost seems like deliberate avoidance. That impression is strengthened by the only two cases that I have discovered of Jefferson actually mentioning the word. In 1807 he hired William Clark to head back to the Ohio territory and make a large collection of bones from Big Bone Lick, the famous site from which all the great mastodon remains had been recovered (before Peale’s then-recent excavations in New York State). When first formally commissioning Clark, Jefferson referred only to collecting “bones.” When he thanked him for the results two years later, he also wrote of “bones.” But in his private account book he made a different annotation. The entry for February 9, 1808, reads: “Gave ord. on bank US. In favr. Genl. Wm. Clarke for expenses digging fossil bones.” There is a similar notation for November 2 of that year where he used the French spelling “fossile.”

At the very least these entries tell us that Jefferson recognized the status of some remains as having been “dug up,” but from his other writings it is not at all clear that Jefferson thought that his mastodon and Megalonyx remains were actually petrified. He wrote that the Megalonyx remains showed “a small degree of petrification” in addition to being preserved by impregnation by “nitre” from the cave floor. He may even have doubted whether elements found in a marsh or on a cave floor qualified as having been “dug up.”

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