A Harmless Treasure, an exhibition of 16th and 17th century herbals in the Library, first floor, Royal Society of Medicine, 1 Wimpole Street, London, W1G 0AE, 25 February – 27 April 2019, open Monday to Thursday 9 a.m. – 9 p.m., Friday 9 a.m. – 5.30 p.m., Saturday 10 a.m. – 4.30 p.m. Admission free.