Marcet (1769-1858) was an innovative writer of popular introductory science books who also broke new ground with Conversations on Political Economy (1816) which explained the ideas of Adam Smith, Malthus and David Ricardo. She was one of 12 children of a wealthy Genevan merchant and banker, and was educated at home with her brothers. Her studies included Latin (essential for the sciences), chemistry, biology and history. After her mother died she took over the running of the house aged just 15, looking after her younger siblings and acting as her father's hostess at frequent parties of scientific and literary guests. She also studied painting with Joshua Reynolds and Thomas Lawrence and this artistic training later enabled her to illustrate her own books. In 1799 she married Alexander Marcet who became a well-known physicist and their shared interest in science led them to conducting experiments in a home laboratory. The couple were part of a literary and scientific social circle including Mary Somerville, Harriet Martineau and Maria Edgeworth. In 1805 Marcet wrote the first of her expository books on subjects including chemistry, botany, religion and economics, written in the format of dialogue between two pupils and their teacher, although it was not published until 1819 as Conversations on Natural Philosophy. This work, published in 1830, takes the form of letters home to her mother from a girl visiting her uncle's family, giving an account of all she learns on a variety of subjects.