File:A text-book of radiology (1915) (14755321834).jpg

Identifier: textbookofradiol00mort (find matches)
Title: A text-book of radiology
Year: 1915 (1910s)
Authors: Morton, Edward Reginald, 1867-
Subjects: X-rays Cathode rays Ohm's law Fluorescence X-rays Radiography X-Rays Radiography
Publisher: New York : E.B. Treat & Co.
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
upon the amount of electrical energy putthrough the tube, larger and more powerful coils wereused, and this necessitated the construction of tubescapable of withstanding such conditions. A modern coileven when working at one-half or perhaps one-quarter ofits full capacity would melt and perforate the platinumanode of one of the original tubes in a few seconds. Theterms anode and anti-cathode are more or lessinter-changeable, as they often refer to the same thing—the anode acting as the anti-cathode in the original and p Morton. ^ 34 TEXT-BOOK OF RADIOLOGY. many of the later X-ray tubes. In most a separate anodeis supplied which may or may not be joined externally to the anti-cathode, and this has the effect of making thetube steadier in action. (See Fig. 12.) In this diagram of an X-ray tube the interrupted linesrepresent the cathode rays and the straight lines theX-rays. In use a focus tube as here described is connected to thepoles of the instrument from which we get the necessary
Text Appearing After Image:
Fig. 12. Plan of a Modern X-ray tube. high potential current of electricity—the anode of thetube being joined to the positive pole and the cathode to the negative—and as the induction coil is the one in mostgeneral use at present, I will assume this except whenotherwise specified. The coil being set in action the tube lights up at once,and that half of the tube lying in front of the plane ofthe anode is seen to be flourescing with a bright applegreen colour. A little irregular and faint greenfluorescence is often seen behind the plane of the anode,but is very small in a well-made tube. This rear half ofthe tube is generally dark, but so long as the vacuum is USE OF X-RAY TUBES. 35 not too high there is usually seen a small blue-violet cloudfloating in space, as it were, just behind the anode. If we now take a barium-platino-cyanide screen andexamine the vicinity of the tube we find that the screenfluoresces brilliantly so long as it is in front of the planeof the anode, and that it

Note About Images