historyNLM Circulating Now1895–1896
Photography of the Invisible and Its Value in Surgery
In 1895 Wilhelm Röntgen announced a mysterious radiation that could pass through the body and expose the bones on film. Within nine months, American physician William J. Morton had published a practical guide to making these X-ray photographs. Early calibration was crude: operators judged penetration by viewing their own hand against a fluoroscope screen, and nobody understood the risk. Many pioneers later died of cancers caused by the radiation. It took more than two decades for doctors to learn to read the images and combine them with listening, touching and questioning patients.
X-rays are high-energy electromagnetic waves. Dense material such as bone absorbs more of them than soft tissue, so less reaches the photographic plate behind the body, leaving a pale shadow of the bones. Early tubes produced rays of varying hardness, so operators had to tune exposures by feel, which made images inconsistent.
X-rays let doctors look inside the living body without surgery, changing diagnosis permanently. The early years show how a powerful new tool can outpace understanding of its dangers, a lesson later applied to radiation safety. Morton's little book shows how quickly the technology spread from physics labs into ordinary clinics and dental offices.
Röntgen's first published X-ray image showed the bones of his wife's hand, with her wedding ring visible.
U.S. National Library of Medicine
Illustrative photo · Wilhelm Röntgen, Public domain, via Wikimedia Commons
