1891 – Born on the 5th of July in Yonkers, New York.
1915 – He was educated at Columbia University, where he earned his PhD in chemistry.
1929 – He isolated and crystallized the gastric enzyme pepsin and determined that it was a protein.
1938 – He isolated and crystallized the first bacteriophage and determined that it was a nucleoprotein.
1916 – He was employed by the Rockefeller Institute for Medical Research in New York City.
1987 – He died on the 27th of May in Wickenburg, Arizona.