First circulatory diagram explaining how a national economy works. It was a contribution to economics by French physician and economist François Quesnay. Contrary to the prevailing mercantilist thought at the time, which saw in the possession of gold, silver and other precious metals the wealth of a country, Quesnay argued that real wealth came from production.
However, his Tableau was drawn considering agriculture as the only source of wealth, which gave his findings limited use, since industrial activity was gaining importance.