In the middle of the 19th century, Claude Bernard studied how the body transforms what we eat. Thanks to Lazzaro Spallanzani we knew the liquid in our stomachs, called gastric juice, was responsible for digestion. Bernard tested dog urine to find out how the body absorbed sugar and concluded that digestion transformed sugar into something undetectable. Further experiments found that the liver always contained sugar, even if none was consumed. He continued with more and more experiments to eventually prove that the liver produces sugar. Not only did Bernard make an important discovery, but he developed a new scientific testing method based on six distinct steps: observation, hypothesis, experiment, result, interpretation, and conclusion. This scientific method is still applied to this very day.