Historic Structures

Stenton Mansion - James Logan Home, Philadelphia Pennsylvania

Date added: August 24, 2018 Categories: Pennsylvania House Georgian

James Logan, one of the founders of the American scientific school, is relatively unknown today. Perhaps because he wrote little, perhaps because Benjamin Franklin's image is so dominant, the Nation has shown little interest in a man who erudition and work almost equalled the sagacity and achievements of Franklin. Logan "was a kind of universal man in the Renaissance tradition statesman, writer, scientist, philosopher," says a biographer; and as a scientist he demands consideration in any study of American science.

Born in the north of Ireland in 1674, Logan arrived in Philadelphia in 1699 as William Penn's secretary. Logan, during the next fifty years, occupied a key position in the affairs of Pennsylvania, contributing much to the rapid and successful development of the colony. His seat in the colony's council underscored his political influence, and between 1731-39 he acted as the chief justice of Pennsylvania's court system. Moreover, throughout Logan's career he was the colony's best and most respected negotiator with the Indians. His public life did not prevent him from amassing a fortune from the fur trade, however, which enabled him to retire to his country estate, "Stenton," in 1730. Even so, when Pennsylvania faced a crisis in 1736, Logan did not hesitate to re-enter public service, and he became acting governor.

Logan's strenuous public career did not prevent him from pursuing his interest in science. Even as a youth, his fascination with mathematics and botany had been great, and as an adult he studied both subject intensively. He assembled the outstanding scientific library in the English colonies. His near 400 scientific and mathematical works even surpassed Harvard College's library in 1735. Logan is reputed to have imported Pennsylvania's first copy of Sir Isaac Newton's Principia Mathematica. More importantly, he read and understood that monumental work, though only selftaught in mathematics.

With such a library at his command, Logan applied himself to various scientific problems. Numerous published papers resulted. One dealt with the motion of the moon. Another suggested improvements in the quadrant; and third outlined improvements in lenses. Ironically, although Logan's great scientific love was mathematics, he realized his greatest accomplishment in botany.

Through a carefully thought out and controlled experiment, Logan proved the vital role of the male element, pollen, in the fertilization of corn. The theory of "preformation," that the wind carried the male element to the female element in plants, first stimulated Logan when in 1726 he read William Wollasto's Religion of Nature Delineated. Additional reading convinced him that a male seed was just as vital to plants as the female seed, and in the summer of 1727 he tested his hypothesis on corn. Logan removed the tassels from some stalks and the filaments from others, and then he watched the development of the kernels. The results clearly showed "that the pollen was the male element and that it was necessary for the production of viable seed." He repeated the experiment in 1728, but delayed making his findings public until 1735-36.

The announcement of Logan's experiment excited many in Europe. Not the members of the Royal Society of London at first, it is true, for when Logan's report was read most of those present paid small attention as they concentrated on dissecting a German cabbage and an Indian turnip. Elsewhere, scientists hailed Logan, the great Dutch botanist, Linnaeus, writing Logan in 1738 that he should be placed "among the demigods of science." Subsequently, the Dutchman used the results of Logan's investigation in a paper on the sexuality of plants that received a prize from the Imperial Academy of Sciences at St. Petersburg in 1760. And Logan's botanical discovery remained influential for several decades after 1800.

Even if Logan had not succeeded in his experiment with corn, he would still be remembered in the history of American science. It was Logan who did so much to stimulate the botanical career of John Bartram. The first books on botany that Bartram read, for example, came from Logan's library. In addition, when Logan died on October 31, 1751, he left his library to the City of Philadelphia a scientific treasure of immense value for such a young city.