Jefferson's Shadow: The Story of His Science by Keith Thomson (review)

Among the pursuits for which Jefferson is known and discussed today, his science is perhaps the least controversial. However, in the late eighteenth and early nineteenth centuries Jefferson was at the center of raging disputes over the quality of life forms in the New World. He was passionate in his scientific inquiry, driven by a determination to demonstrate that the natural history of America was equal if not superior to that of Europe. Keith Thomson sets the story of Jefferson's science in that historical context.

A professor emeritus of natural history at Oxford University, Thomson is an executive officer at the American Philosophical Society, of which body Jefferson once served as president. The author's source of inspiration for Jefferson's Shadow was his tenure as a visiting fellow at the International Center for Jefferson Studies at Monticello when he wrote A Passion for Nature, in the Monticello Monograph Series. He has written widely on natural history, paleontology, and evolution.

Jefferson's life as a scientist began with his early education. Thomson attributes a part of his subject's propensity for observing, measuring, and cataloging to his parents. Peter Jefferson, a surveyor who was passionate about record-keeping, farmed a large estate. Jane Randolph Jefferson came from a family of botanists and avid gardeners. From early in life Jefferson kept a garden diary and recorded meteorological observations. The data he collected over the years made major contributions to the fields of natural history, climatology, geology, and paleontology.

Jefferson's Notes on the State of Virginia was rich in observation and responsive to European curiosity about the New World. There was much misinformation on the Continent regarding the true nature of the emerging nation. The secretary to the French delegation in Philadelphia was directed by the French government to write to authorities in each of the newly independent states requesting answers to specific questions on rivers, ports, natural riches, laws, institutions, militias, and peoples. In addition to being a formal description of the laws and conventions, geography, and commerce of one state, and a comprehensive compendium of its natural history, Jefferson's Notes was a personal manifesto extolling Virginia's virtues (46).

Thomson's title is Jefferson's own characterization of the observations he reported in Notes: "The work is nothing more than the measure of a shadow, never stationary, but lengthening as the sun advances, and to be taken anew hour to hour" (3).

Beyond pure knowledge, science was a political tool for Jefferson. The highly respected French naturalist, Comte de Buffon, was convinced that the New World was dismal and inhospitable, resulting in indigenous life that was sparse and weak. Jefferson steadfastly collected data to refute Buffon. He went so far as to send a box to the Comte containing parts of American mammals including a moose, which species is much larger than the caribou, the largest animal in Europe. The long voyage took its toll on the contents. Buffon was impressed, if unconvinced.

The scientific community on both sides of the Atlantic debated the origin of mountains, the presence of what appeared to be shells at high elevations, and the significance of large petrified bones that were referred to only as "fossils" (based on the Latin origin of that word, meaning "dug up"). Jefferson never used this term, preferring "large bone." Though Jefferson admired and understood Newton's theories on mechanics and mathematics, he lived in a time of transition between traditional (e.g., biblical or ancient Greek) explanations and those belonging to the Age of Reason (75). An example of the sort of explanation popular at the time was that the presence of bones of large species resembling hippopotami and elephants in a region with frigid winters was due to their having been washed there by the biblical flood of Noah (56).

Thomson devotes a chapter of the book to the debate over the identity...