 His anatomic treatise "De humani corporis fabrica" exposed many anatomical errors in Galen and advocated that all surgeons should train by engaging in practical dissections themselves.The second figure of importance in this era was Ambroise Paré (sometimes spelled "Ambrose" (c. 1510 – 1590)), a French army surgeon from the 1530s until his death in 1590.The practice for cauterizing gunshot wounds on the battlefield had been to use boiling oil, an extremely dangerous and painful procedure.