Logan, James (1674–1751), scientist and public servant in America, was born 20 October 1674 at Lurgan, Co. Armagh, son of Patrick Logan, a schoolmaster and former Church of Scotland clergyman who became a quaker, and his wife, Isabel Logan (née Hume) – both had moved to Ireland from Scotland to avoid persecution. Educated initially by his father, James Logan was largely self-taught and read voraciously throughout his life. He served a brief apprenticeship with Richard Webb, a Dublin linen merchant, before his family fled back to Scotland during the Jacobite wars. In 1690 his family moved to Bristol and in 1694 he was put in charge of the Friar Meeting House quaker school there, replacing his father who returned to Ireland. Around 1697–9 Logan attempted to work in the linen trade again, when the quaker leader William Penn invited him to accompany him to America. His brother William Logan (1686–1757) remained in Bristol where he became a physician; he corresponded regularly with James on scientific matters.
Settled in America, Logan became involved in the fur trade in 1711, using methods that were certainly unscrupulous and bordered on the illegal: he sold rum to Native Americans and left many fur traders in debt. As Penn’s secretary, he was closely involved in many of the details of the settlement of Pennsylvania. He was a respected figure in his own right, serving as secretary of the province and clerk of the provincial council of Pennsylvania (1701–17). Other prominent offices followed: he served as mayor of Philadelphia (1722–3), was a chief justice in the supreme court of Pennsylvania (1731–9) and was acting governor of Pennsylvania (1736–7). He was also a founding trustee of the College of Philadelphia, the predecessor of the University of Pennsylvania. Throughout his life he continued to represent the interests of Penn and his heirs as administrator, lawyer and merchant.
Through his investments in land, and his trade with Native Americans, with whom he was always on good terms despite his practices, Logan became very wealthy. A well-read man, he had an extensive library, and was recognised for his expertise in mathematics, natural history and astronomy. He published numerous scholarly papers on optics and botany and his pioneering work on the pollination of plants, begun in 1727, marked a breakthrough in plant hybridisation as he recognised that maize reproduced sexually. His most important scientific contribution, however, was not his own research but his role as advisor to others. He tutored the American botanist John Bartram in Latin and introduced him to the famous Swedish botanist Lineaus. He also advised Benjamin Franklin in his research.
On 9 December 1714 he married Sarah Read, the daughter of Charles Read, a merchant; they had five children. He died 31 October 1751, at Germantown, Pennsylvania. Aristocratic in bearing, and in outlook, Logan is recognised as the leading intellectual scientist of his time. In 1742 he decided to bequeath his vast library to the public, and this request was carried out by his son, James, after his death. First housed at the Bibliotheca Loganiana, the 2,184 volumes are now stored at the Library Company of Philadelphia and are recognised as the finest collection assembled in pre-independence America. Logan’s eldest son, William (1718–76), succeeded him as the Penn family advisor.