This Article Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Spiers, F. W. Search for Related Content PubMed PubMed Citation Articles by Spiers, F. W.

A note on Roentgen's X-ray absorption measurements in 1895

Formerly of the Medical Physics Department, University of Leeds

This excerpt was created in the absence of an abstract.

Among the many observations made by Roentgen in his first paper, the most important and revolutionary for medicine were those on the transmission of X rays through normally opaque materials, notably through tissues of the body. In a single sentence he founded the science of radiology: "If one holds the hand between the discharge apparatus and the screen, one sees the dark shadows of the bones within the much fainter shadow picture of the hand itself" (Roentgen, 1895).

Further absorption experiments were made by Roentgen as well as, in particular, measurements on transmission through metal sheets. In Section 5 of his first paper, Roentgen wrote: "Platinum, lead, zinc and aluminium were rolled out in sheets of such thickness that all appeared nearly equally transparent", the detector being his barium platinocyanide fluorescent screen. He measured the thickness of the sheets and gave the values as in the left-hand part of Table I, which reproduces the table from Roentgen's paper. Besides the thicknesses in mm, he also gave the relative thicknesses and the densities of the metals and commented: "These values show that by no means is the transparency of different metals equal if the product of thickness and density is the same".

Received for publication March 1, 1986.