In diseases of bone, which are obscure, it has already proved of great advantage, as in a case related by Mr. Abrahams ("British Medical Journal," February 22, 1896). A lad of nineteen, who had injured his little finger in catching a cricket ball, had the last joint of the finger bent at a slight angle, and he could neither flex nor extend it. Any attempt to do so caused great pain. The diagnosis was made of a fracture extending into the joint, and that the joint having become ossified, nothing short of amputation would give relief. Mr. Sydney Rowland skiagraphed the hand, and showed that there was only a bridge of bone uniting the last two joints of the finger. An anaesthetic was administered, and with very little force the bridge of bone was snapped, the finger saved, and the normal use of the hand restored. Deformities of bone can be admirably shown. Thus Figure 9 ("British Medical Journal," February 15, 1896) shows the deformity of the last two toes of the foot, due to the wearing of tight shoes. (Owing to the accidental breaking of the plate, only a part of the foot is shown.) The lady whose foot was thus skiagraphed stated that she had suffered tortures from her boots, so that walking became a penance, and she even wanted the toes amputated. Relief was obtained by wearing broad-toed boots, which gave room for the deformed toes. Another admirable illustration of a similar use of the method is seen in Figure 2, from a case of Professor Mosetig in Vienna. The last joint of the great toe was double the ordinary size, and by touch it was recognized that there were two bones instead of one. The difficulty was to determine which was the normal bone, and which the extra bone that ought to be removed. The moment the skiagraph was taken, it was very clear which bone should be removed. Bony tumors elsewhere can also be diagnosticated and properly treated. Possibly, also, we may be able to determine the presence of dead bone, though I am not aware of any such skiagraphs having been taken. [Illustration: FIGURE 8.--SKIAGRAPH OF THE LEFT FOREARM OF A LIVING SUBJECT, SHOWING AT THE POINT MARKED "B" A DEFORMITY FROM AN OLD FRACTURE. (Taken at the State Physical Laboratory, Hamburg, and published in the "British Medical Journal.")] Diseases and injuries of the joints will be amenable to examination by this method. Figure 10 shows an elbow joint with tuberculous disease. The bones of the arm and forearm are clearly seen, and between them, is a light area due to granulation-tissue, or to fluid, probably of tuberculous nature, which is translucent to the rays. The picture confirms the prior diagnosis of tuberculous disease, and shows that the joint will have to be opened and treated for the disease. Deposits of uric acid in gouty diseases of the joints will undoubtedly be shown by these methods, but this will scarcely be of any help in the treatment. Whether light will be thrown on other diseases of the joints is a problem not yet solved.