Physician Jean-Baptiste Denys performed the first human blood transfusion. He introduced 350 ml of blood into a lamb to a 15-year-old boy. The boy had had a fever for two months and his parents were willing to try anything. After blood transfusion the following morning, it is believed that the young man was cured and was considered a success. Although the physician Jean-Baptiste Denys became highly renowned among European scientists in a short time, his end of life was altered by several trials and deaths.