Answer: One hand
X-rays were discovered in 1
Fascinated by the discovery and its implications, Röntgen even invested in studying what he called X-rays (the X meant the unknown, since he first had to figure out exactly what he was dealing with). In the course of his research he came across what would prove to be the most important element of his discovery: the medical use of X-rays. After guiding X-rays through various materials and items from his lab, he exposed a photo plate with his wife's hand resting on it. Seeing her bones in the film like a skeleton, she exclaimed, "I've seen my death."
The medical application of his discovery was obvious to him, and Röntgen immediately set about his findings publish and promote. It is estimated that in 1896 alone, 49 essays and 1,044 articles on X-rays and their potential for revolutionizing medicine were published. The first use of X-rays for medical diagnosis was made the same year that the English physician John Hall-Edwards used them to find a needle that was in the hands of one of his co-workers and later for surgical use.