The dense shadows cast by bone are, at least at present, an insuperable obstacle to skiagraphing the soft translucent organs of the body which are enclosed within a more or less complete bony case, as the rays will be intercepted by the bones.  Efforts, therefore, to skiagraph the heart, the lungs, the liver, and stomach, and all the pelvic organs, probably will be fruitless to a greater or less extent until our methods are improved.  While a stone in a bladder outside the body would undoubtedly be perceptible, in the body the bones of the pelvis prevent any successful picture being taken.

[Illustration:  FIGURE 6.—­SKIAGRAPH OF A DEAD HAND AND WRIST, SHOWING TWO BUCK-SHOT AND A NEEDLE EMBEDDED IN THE FLESH.

("American Journal of the Medical Sciences,” March, 1896.)]

To turn from the hindrances to the advantages of the application of the method to the bones, one of the most important uses will be in diseases and injuries of bones.  In many cases it is very difficult to determine, even under ether, by the most careful manipulations, whether there is a fracture or a dislocation, or both combined.  When any time has elapsed after the accident, the great swelling which often quickly follows such injuries still further obscures the diagnosis by manipulation.  The X rays, however, are oblivious, or nearly so, of all swelling, and the bones can be skiagraphed in the thinner parts of the body at present, say up to the elbow and the ankle, with very great accuracy.  Thus, Figure 8 shows the deformity from an old fracture of the ulna (one of the bones of the forearm) very clearly.

By this means we shall be able to distinguish between fracture and dislocation in obscure cases.  Thus Mr. Gray ("British Medical Journal,” March 7, 1896), in a case of injury to an elbow, was enabled to diagnosticate and successfully to replace a very rare dislocation, which could not be made out by manipulation, but was clearly shown by the X rays.  We may also possibly be able to determine when the bones are properly adjusted after a fracture; and all the better, since the skiagraph can be taken through the dressings, even if wooden splints have been employed.  If plaster of Paris is used (and it is often the best “splint”) this is impermeable to the rays.

That this method will come into general use, however, is very unlikely, since the expense, the time, and the trouble will be so great that it will be impracticable to use it in every case, especially in hospitals or dispensaries, where crowds of patients have to be attended to in a relatively brief time.  In the surgical dispensary alone of the Jefferson Medical College Hospital, about one hundred patients are in attendance between twelve and two o’clock every day, and all the time of a large number of assistants is occupied with dressing the cases.  It would be manifestly an utter impossibility to skiagraph the many fractures which are seen there daily, considering that it would take from half an hour to an hour of the time of not less than two or three assistants skilled not only in surgery, but also in electricity, to skiagraph a single fracture.  Now and then, in obscure cases, however, the method will be undoubtedly of great service, as in the case above described.