One of those extraordinary discoveries which startle the whole world
came nearly at the end of the nineteenth century, in the winter of
1895–96. At that time a modest professor in the University of Würzburg
announced that he could readily see the skeleton inside the body
through the flesh! Naturally, the first announcement was received with
almost absolute incredulity; but very soon his discovery was confirmed
from all sides, and it has now taken its place among the recognized
phenomena of science. By means of certain rays, which, being of unknown
nature, were called “X”-rays, after the well-known mathematical X, or
unknown quantity, Professor Röntgen has shown us that not only can the
bones be seen, but that almost every substance in the body can be seen
and reproduced in pictures. The reason for this is because they are
all obstacles to the passage of these X-rays and so produce shadows
on a sensitized photographic plate. If the exposure is sufficiently
prolonged the rays penetrate even through the bones and act upon the
photographic plate, so that no shadow remains. If the rays are allowed
to penetrate for a shorter time the bones show dense shadows, and one
can get a light shadow of the soft parts. If the exposure is still
shorter, then we can recognize the dense shadow of the bone, the much
less dense shadows of the muscles, and the still lighter shadows of
the layer of fat immediately under the skin. The heart can be seen
beating, and its shadow is now a well-recognized feature in skiagraphs
of the chest. At first it was thought impossible to discover anything
inside the bony skull, but there are now on record nearly a score of
instances in which bullets have been detected within the skull, and
after trephining have been found and removed exactly at the location
indicated. It is a very common thing now to locate a piece of steel
or other similar foreign bodies within the eyeball by the method of
Dr. Sweet, or some similar method, within one or two millimetres (a
millimetre is one-twenty-fifth of an inch). It is now well recognized
that even stones in the kidney will throw shadows sufficiently strong
for them to be recognized, and by noting their level in relation to
the vertebræ we can tell precisely in what part of the kidney to make
the incision in order to find and remove them. It has happened to
myself and many other surgeons in the past to cut down upon a kidney,
believing that there was a stone in the kidney, only to find that we
had been misled by the apparently clear symptoms of such a foreign
body. In future no such mistake should be made by any surgeon within
reach of a skilful skiagrapher. Unfortunately, gall stones and numerous
other foreign bodies, vegetable substances such as beans, corn, wood,
etc., being as transparent to the X-rays as are the soft parts, are not
revealed by means of this new method of investigation; but cavities
in the lung, abscesses in bone, and similar diseases which produce
thinning of the lung, bone, and other such organs, and so lighten
instead of deepen the shadows, can now be recognized by means of light
spots in the pictures as well as others by means of a shadow.
I spoke a moment ago of the need of a “skilful” skiagrapher, for
it must be remembered that there may be the same difference in the
personal skill, and, therefore, in the reliability of the results in
skiagraphy as there is in photography. A poor photographer will get
very different results from a skilful one, even if he uses precisely
the same quality of plates and precisely the same camera. Personal
skill and experience in the skiagrapher is, therefore, one of the most
important elements in success. It must be remembered also that the
X-rays in not a few cases may mislead us. I have, personally, fractured
a bone on account of deformity, taken an X-ray picture immediately
after the operation, the picture showing not the slightest evidence
of a fracture, which I absolutely knew existed. Moreover, foreign
bodies found on the outside of the person may mislead us, as, for
example, the metal part of suspenders, a coin in one’s pocket, and
such like. They look in the picture as if they were inside rather than
outside the body, and any article the shape or size of which would not
reveal its nature might easily be mistaken for a foreign body within
the patient. Therefore, in many cases only an expert can determine
precisely what the skiagraph means. I especially mention this, because
there is a tendency at present to utilize skiagraphs in court in
order to convince the jury that such a picture is an evidence of
malpractice. Such pictures always need an interpreter in order to judge
correctly of their meaning. It is precisely as if the jury were asked
to look through a microscope. I have been myself accustomed to use the
microscope for thirty years, but there are many instances even yet in
which I am obliged to ask a pathologist or bacteriologist what I really
am looking at in the microscope. While one may make a mistake of small
moment in some cases, yet if a man’s life or liberty or purse is at
the mercy of a jury which does not know how to interpret a skiagraph,
and, may, therefore, give a verdict which is “precisely wrong,” as
Professor Lincoln, my old teacher of Latin, used to call many of our
translations, it will be a very serious matter and lead to gross
injustice.