Although Nikola Tesla is best known for his work with electricity he made significant contributions in many scientific areas, one was in the field of Roentgen rays, better known today as x-rays. Collected here are nine essays on Roentgen rays. Nikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer. He was an important contributor to the birth of commercial electricity, and is best known for developing the modern alternating current (AC) electrical supply system. Tesla's patents and theoretical work also formed the basis of wireless communication and the radio.