These are letters to Woodward, usually only one letter per correspondent, concerning his professional appointments, and botanical and geological research and publications. There is also scattered information regarding the Geological Society of London, and the British Museum, but little substantive material on Woodward himself.

Adam Sedgwick (1785-1873, APS 1860), geologist, was an important figure in the development of the modern discipline of geology. He was educated at Cambridge, being ordained in 1817. An excellent field geologist, he did significant work interpreting complex old rock in such places as Devonshire (naming the Devonian Period after that location), Cornwall, and the Lake District, correlating his findings with strata in places such as Germany. Sedgwick first interpreted strata from the period he named Cambrian. He served in many professional organizations and was honored for his work with the Wollaston and Copley medals. Sedgwick, a Liberal in politics, served on committees that reformed the administration of university education. Despite being a friend of Charles Darwin's, Sedgwick was critical of the materialist bent of Darwinian thought. The 37 letters in the collection were acquired at various times, mainly through purchase, and assembled for the collection. The letters span the dates 1825-1870. Individually most letters are not especially significant, but collectively they touch on most aspects of Sedgwick's life and career. There are letters about Sedgwick's work on university reform, the Geological Museum at Cambridge, lectures, colleagues, travel, health, and family. Only one letter in the collection delves into detail about Sedgwick's geologic work.

The natural historian Richard Harlan was a pioneer in the study of comparative anatomy and vertebrate paleontology in the United States during the years following the War of 1812. Having received his medical degree from the University of Pennsylvania in 1818, Harlan was employed as an instructor of anatomy at Joseph Parrish's school and at the Philadelphia Museum. A practicing physician and member of the Academy of Natural Sciences of Philadelphia and the American Philosophical Society, Harlan made important contributions in comparative neuroanatomy, paleontology, herpetology, and systematic zoology. He died shortly after moving to New Orleans in 1839. Harlan's journals document two of the three overseas voyages he undertook during his lifetime. The first took place in 1816-1817 when Harlan was still a medical student, accompanying an East Indiaman to Calcutta as ship's surgeon. The second took place when Harlan was at the peak of his career in 1833, venturing to England, France, and Italy to strengthen contacts with European colleagues. Interesting travel narratives in themselves, the journals mingle enthusiasm for the new and exotic with a touch of Harlan's truculance. The European journal includes a valuable account of the 3nd meeting of the British Association for the Advancement of Science at Cambridge at which Harlan delivered a paper on fossil reptiles.

There is correspondence concerning geology, botany, natural history, natural selection, evolution, British science and scientists, and other scientific topics. Most of the letters are written by Lyell, with a very few items by others.