John Richardson Young

John Richardson Young (1782 – June 8, 1804) was an American physician and considered one of the earliest pioneers of experimental physiology and biochemistry in the United States.

He then practiced with his father at Hagerstown before joining Pennsylvania University where he graduated in 1803 with a thesis titled "An Experimental Inquiry into the Principles of Nutrition and the Digestive Processes."

Young's teachers included the physician Benjamin Rush and the chemist James Woodhouse.

In his thesis, Young documented his experiments conducted on bull frogs and he rejected the contemporary idea that digestion involved fermentation or putrefaction and demonstrated that food was dissolved in the stomach by an acidic juice and that the mass then went to the duodenum where it mixed with bile and pancreatic juice.

[3][4] Since he had used a frog as an experimental model, he was able to show that neither mastication nor heat had a major role in digestion.