Statistics for occurrence #1 of “Dr. John C. Warren” in entry morton-william-thomas-green of Harper's Encyclopedia of United States History:

...ain. Assured of its safety by experiments on himself, he first administered it successfully in his dental practice Sept. 30, 1846, extracting a firmly rooted tooth without pain. At the request of Dr. John C. Warren , ether was administered to a man in the Massachusetts General Hospital, from whose groin a vascular tumor was removed while the patient was unconscious. Dr. Morton obtained a patent for his discove...
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