Published Den Waaragtigen Omloop des Bloeds (On the True Circulation of Blood), Letter 65

November 1, 1688

Publication by Voorstad in Delft of Den Waaragtigen Omloop des Bloeds, On the True Circulation of Blood in Eels, which Leeuwenhoek considered his showcase experiment, the one he entertained visitors with. The letter was dated September 7, 1688, so first publication of the pamphlet, while dated only 1688, was probably later that year, likely not the November 1 listed here to keep the database happy.