Clarence Madison Dally

Clarence Madison Dally (January 8,[1] 1865 – October 2, 1904[2]) was an American glassblower, noted as an assistant to Thomas Edison in his work on X-rays and as an early victim of radiation dermatitis and its complications.

He was entrusted to help demonstrate Edison's new fluoroscopic machine at the 1896 National Electric Light Association exhibition.

[6] Some sources list Clarence Dally as having been on standby with the X-ray equipment in Buffalo, New York, in case it was to be needed by doctors operating on President William McKinley after he was shot on September 6th, 1901.

By 1900, Clarence Dally was suffering radiation damage to his hands and face sufficient to require time off work.

These procedures failed to halt the progression of his carcinoma, and despite the amputation of his arms at the elbow and shoulder, he died from mediastinal cancer.

Edison using a calcium tungstate flouroscope to examine a hand by X-rays. The man with Edison has been identified as Thomas Commerford Martin but may be Clarence Dally.