Regnier de Graaf, Dutch physician and anatomist (d. 1673)
Regnier de Graaf (English spelling), original Dutch spelling Reinier de Graaf, or Latinized Reijnerus de Graeff (30 July 1641 – 17 August 1673) was a Dutch physician, physiologist and anatomist who made key discoveries in reproductive biology. He specialized in iatrochemistry and iatrogenesis, and was the first to develop a syringe to inject dye into human reproductive organs so that he could understand their structure and function.