This collection contains diaries, weather records, and commonplace books of Thomas Thistlewood for the years 1748-1786. His diaries (37 volumes) cover two years in England (in London and in Lincolnshire) and the remaining time in Jamaica (1750-1786). This is a rich source for agricultural, daily routines, slave life, folklore, natural history, medical diagnosis and remedies, the intellectural world of an Anglo-Jamaican, his sex life, and the climatic history of Jamaica. There are also miscellaneous volumes, such as a list of slaves, 1758-1766. Included in the collection is the journal of his nephew, John Thistlewood, 1763-1765, describing his voyage to Jamaica and life on his uncle's plantation.

Raymond Pearl spent the majority of his academic career (1918-1940) at Johns Hopkins University, where he was Professor of Biometry and Vital Statistics and Director of the Institute of Biological Research. Founder of the Quarterly Review of Biology and Human Biology, he made significant contributions in the areas of biology, genetics, eugenics, and statistics. The Pearl Papers includes correspondence as well as notebooks, scrapbooks, diplomas, photographs, and 33 volumes of diaries. There is significant correspondence with his wife, Maud (ca. 500 letters), and mother, Ida May (ca. 300 letters), particularly for the years 1895-1934. Of special note is Pearl's correspondence with his friend, colleague, and fellow Baltimoreian, H. L. Mencken (ca. 500 letters). The collection contains important information on the American Association of Physical Anthropologists, The Baltimore Sun, the Birth Control Federation of America, Dartmouth College, the International Institute of Statistics, Johns Hopkins University, and the National Academy of Sciences. This note is currently under review for revision.

One of the oldest houses in Philadelphia, Wyck is now a non-profit museum listed on the National Register of Historic Places. Nine generations of the Jansen-Wistar-Haines family owned the Wyck property from 1690 until 1973. The last family owner deeded 2.5 acres of land, the house and its contents, several outbuildings, a landscaped garden, and a small endowment to the Wyck Charitable Trust. The Wyck Charitable Trust and the Wyck Association now administer the preservation of the property and its educational services to the public. This collection contains diaries, letters, accounts, bills and receipts, deeds, and photographs. The collection as a whole is deepest for the period 1770-1970. Items of particular note include accounts of household expenses at Wyck from ca. 1790-1970; papers pertaining to the Academy of Natural Sciences of Philadelphia, Quaker schools, and social reform groups; agricultural and horticultural practices; and correspondence to and from cultural leaders of 18th and 19th century Philadelphia. The papers of the John S. Haines family (Ms. Coll. 52A) form part of the Wyck Papers. The papers cover the years 1845 to 1949 and are arranged into eight series.