Caption

Bloodletting chart. Engraving of a historical bloodletting chart with zodiac signs (at right) and alchemy symbols (at left). The engraving is known as Aderlassmann. It was believed that illnesses were the result of an imbalance in bodily fluids. For example high blood pressure was due to too much blood. The treatment was letting excess blood through a cut or by using leeches. The alchemy symbols were drawn by Paracelsus, a 16th century physician who believed the alchemic principle, 'everything tends towards perfec- tion', could be used to find a universal medicine. The engraving is from a German encyclopaedia known as Bilder Atlas (F.A. Brockhaus, Germany, 1895).