Today in History is a daily newsletter from Britannica. (more) Today in History—June 15: The First Blood Transfusion Written by Kara Rogers Kara Rogers is the senior editor of biomedical sciences at Encyclopædia Britannica, where she oversees a range of content from medicine and genetics to microorganisms. She joined Britannica in 2006 and... Kara Rogers Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated June 10, 2026 •History On this day in 1667, a French physician attempted something no one had ever done before: a blood transfusion. Specifically, he transfused blood—not from a human, but from a sheep—into a teenage boy suffering from a severe fever, fully documenting the procedure’s signs and symptoms. Today in History is a daily newsletter from Britannica. Encyclopædia Britannica, Inc. Want to learn more about what happened on June 15, or any other day of the year? Sign...

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