Medical knowledge is a fundamental part of human existence, but its relatively uniform diffusion in a universal language that could be understood by all professionals developed considerably during the 19th century. The two greatest developments in this field both occurred during the 1840s and consisted of pain control via anaesthesia and the discovery of hygiene as a method of preventing disease. Modern medicine is built on these two fundamental pillars.       The study of the human anatomy continued to be the basis of all medical practices during the 19th century. Everything that could be seen, heard, felt and smelt was thoroughly examined.      In 1846, Doctor Semmelweis noticed that the number of puerperal fever victims was higher in one room of the Vienna Hospital than in others. After carrying out numerous intuitive tests, he proved that cleaning his hands after dissecting cadavers or attending other patients reduced the mortality rate to less than 1%.        Measuring, checking, experimenting, analysing, counting, compiling statistics, discerning, classifying, etc. Only that which is evident, demonstrable and repeatable may be admitted as science, whatever the place, context, religious beliefs or traditions. In the 19th century, medicine began to adhere ever more firmly to this philosophy.          M u s e o - Z u m a l a k a r r e g i - M u s e o a Muxika egurastokia 6, 20216 Ormaiztegi (Gipuzkoa) TF: +34 943 88 99 00 Fax: +34 943 88 01 38 mzumalakarregi@kultura.gipuzkoa.net