Edward Abbott undergoes an ether operation

Jenner transferred material from milkmaid Sarah Nelmes’s cowpox lesion to the eight-year-old boy.

Sarah Nelmes supplied the cowpox material used in the experiment; she should be included in the account of the procedure.

The date marks Phipps’s cowpox inoculation, not the later challenge that tested whether he was protected.

The experiment helped develop a distinct smallpox vaccine; variolation had already been practiced in Asia and parts of Africa.

Morton administered ether while Warren operated on Abbott at Massachusetts General Hospital.

The public operation helped spread the use of inhaled anesthesia in surgery.

The demonstration showed that ether could reduce pain; the quality and completeness of Abbott’s anesthesia have been debated.

At a gathering in Edinburgh, Simpson, Keith and Duncan inhaled chloroform and observed its anesthetic effects.

The dated self-experiment helped lead to chloroform use in surgery and childbirth, with safety risks recognized later.

The testing involved several participants; its subsequent publicity focused heavily on Simpson.