© Frank H. Jump
Vincenzo pointed out this billboard on the way to Manhattan. The third and fifth images are unaltered.
X-rays were discovered by Wilhelm Conrad Röntgen on November 8, 1895 – “an achievement that earned him the first Nobel Prize in Physics in 1901.” – Wikipedia
Source image locations:
http://img.dailymail.co.uk/i/pix/2006/12/xrayhallowellAP_468x586.jpg
http://newsimg.bbc.co.uk/media/images/41140000/jpg/_41140324_scans203x.jpg