Darwin's study. View of a variety of chemicals and rock samples in Charles Darwin's (1809-1882) study at Down House, Kent, England. It was in this study that he wrote his revolutionary work On the Origin of Species by Means of Natural Selection (1859). Darwin lived at Down House for the last 40 years of his life, and did all his major thinking and writing there. The chemicals include poisons and preservatives to allow him to bring specimens back from his travels. Darwin was also interested in geology, and some of the chemicals around the rocks would have been used to test their composition. Down House is now open to the public.