Blood, urine, pus, spinal fluid… these bodily fluids play an important role in diagnosis (that is, in the process of determining what ailment a patient is suffering from). The analysis of these fluids takes place in a laboratory, using scientific methods and instruments.

During the 19th century, science began to interact with medicine. By the early 20th century, hospitals were being designed with laboratories right in them—it was like science and medicine were moving in together. Now they are married in such a way that it is hard for us to imagine them apart.