In this video about a new exhibition, the British Library pays homage to the important role data visualisation plays in the scientific process. In this Nature Video, curator Johanna Kieniewicz explores some beautiful examples of visualisations, past and present. One of the first in this video is a diagram made by Florence Nightingale in which she showed how poor sanitation cost more lives of soldiers then their wounds. Soldiers got preventable diseases especially in hospitals. With sanitary reforms there was a dramatic reduction of deaths during the war.It changed the world, it changed science.