"My next object is to photograph the bones of the entire leg," continued Herr Spies. "I anticipate no difficulty, though it requires some thought in manipulation."
It will be seen that the Röntgen rays and their marvellous practical possibilities are still in their infancy. The first successful modification of the action of the rays so that the varying densities of bodily organs will enable them to be photographed, will bring all such morbid growths as tumors and cancers into the photographic field, to say nothing of vital organs which may be abnormally developed or degenerate. How much this means to medical and surgical practice it requires little imagination to conceive. Diagnosis, long a painfully uncertain science, has received an unexpected and wonderful assistant; and how greatly the world will benefit thereby, how much pain will be saved, and how many lives saved, the future can only determine. In science a new door has been opened where none was known to exist, and a side-light on phenomena has appeared, of which the results may prove as penetrating and astonishing as the Röntgen rays themselves. The most agreeable feature of the discovery is the opportunity it gives for other hands to help; and the work of these hands will add many new words to the dictionaries, many new facts to science, and, in the years long ahead of us, fill many more volumes than there are paragraphs in this brief and imperfect account.
THE RÖNTGEN RAYS IN AMERICA.
By Cleveland Moffett.
AT the top of the great Sloane laboratory of Yale University, in an experimenting room lined with curious apparatus, I found Professor Arthur W. Wright experimenting with the wonderful Röntgen rays. Professor Wright, a small, low-voiced man, of modest manner, has achieved, in his experiments in photographing through solid substances, some of the most interesting and remarkable results thus far attained in this country. His success is, no doubt, largely due to the fact that for years he had been experimenting constantly with vacuum tubes similar to the Crookes tubes used in producing the cathode rays.
When I arrived, Professor Wright was at work with a Crookes tube, nearly spherical in shape, and about five inches in diameter—the one with which he has taken all his shadow pictures. His best results have been obtained with long exposures—an hour or an hour and a half—and he regards it as of the first importance that the objects through which the Röntgen rays are to be projected be placed as near as possible to the sensitized plate.
It is from a failure to observe this precaution that so many of the shadow pictures show blurred outlines. It is with these pictures as with a shadow of the hand thrown on the wall—the nearer the hand is to the wall, the more distinct becomes the shadow; and this consideration makes Professor Wright doubt whether it will be possible, with the present facilities, to get clearly cut shadow images of very thick objects, or in cases where the pictures are taken through a thick board or other obstacle. The Röntgen rays will doubtless traverse the board, and shadows will be formed upon the plate, but there will be an uncertainty or dimness of outline that will render the results unsatisfactory. It is for this reason that Professor Wright has taken most of his shadow pictures through only the thickness of ebonite in his plate-holder. A most successful shadow picture taken by Professor Wright in this way, shows five objects laid side by side on a large plate—a saw, a case of pocket tools in their cover, a pocket lense opened out as for use, a pair of eye-glasses inside their leather case, and an awl. As will be seen from the accompanying reproduction of this picture, all the objects are photographed with remarkable distinctness, the leather case of the eye-glasses being almost transparent, the wood of the handles of the awl and saw being a little less so, while the glass in the eye-glasses is less transparent than either. In the case of the awl and the saw, the iron stem of the tool shows plainly inside the wooden handle. This photograph is similar to a dozen that have been taken by Professor Wright with equal success. The exposure here was fifty-five minutes.
A more remarkable picture is one taken in the same way, but with a somewhat longer exposure—of a rabbit laid upon the ebonite plate, and so successfully pierced with the Röntgen rays that not only the bones of the body show plainly, but also the six grains of shot with which the animal was killed. The bones of the fore legs show with beautiful distinctness inside the shadowy flesh, while a closer inspection makes visible the ribs, the cartilages of the ear, and a lighter region in the centre of the body, which marks the location of the heart.
Like most experimenters, Professor Wright has taken numerous shadow pictures of the human hand, showing the bones within, and he has made a great number of experiments in photographing various metals and different varieties of quartz and glass, with a view to studying characteristic differences in the shadows produced. A photograph of the latter sort is reproduced on page 401. Aluminium shows a remarkable degree of transparency to the Röntgen rays; so much so that Professor Wright was able to photograph a medal of this metal, showing in the same picture the designs and lettering on both sides of the medal, presented simultaneously in superimposed images. The denser metals, however, give in the main black shadows, which offer little opportunity of distinguishing between them.