Sanctorius in his balance. Coloured historical engraving of the Italian physician Sanctorius (1561-1636), seated before a meal in a balance. He carried out quantitative measurements of the human body by conducting various daily activities, such as eating meals, whilst seated in the balance. He showed that the body lost weight even while inactive through insensible perspiration". This marks the beginning of the study of metabolism. Sanctorius applied a thermometer to measuring the warmth of the human body thereby establishing the clinical thermometer. He also invented a device to measure the pulse by means of a pendulum. This was known as a pulsilogium."