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By permission of Pathé Frères.
Two of Dr. J. Comandon's earliest Investigations in Radio-cinematography.
1. X-ray moving-pictures of the bending of the knee, showing muscular movement. 2. X-ray film of the opening of the hand.
With this seemingly complicated apparatus it was possible to take any desired number of successive pictures and at any intervals of time with unerring precision.
For these particular experiments a special film was prepared, for the pictures produced by the standard camera were not large enough. Monsieur Carvallo took pictures of a depth of 2⅖ inches instead of the usual ¾ inch. Special arrangements were made also to secure extreme sensitiveness of the emulsion so that it might be more susceptible to the action of the X-rays. The disposition of the film followed special lines, as may be seen by reference to the diagram ([Fig. 9]). The Crookes tube, containing the X-rays, was placed beneath a table provided with an aperture upon which was laid a transparent medium, such as glass, to support the subject under investigation. Above this was placed the gate through which the film was moved intermittently, the sensitized ribbon travelling in a horizontal direction from one spool to the other. In the early experiments a Maltese cross movement was incorporated to provide the requisite intermittent motion to the film, but subsequently a novel claw motion devised by Monsieur Noguès, the mechanician to the Marey Institute, was introduced with far better results.
In carrying out the experiments with different live subjects extreme ingenuity was used in placing and holding the creature so that the most perfect images might be obtained. Monsieur Carvallo devoted his energies largely to radio-cinematographing the functions of digestion, and selected such subjects as fresh-water fish, toads, frogs, lizards, birds, and mice. Thus he obtained comparative results from five species of the animal kingdom. The subjects were fed first with a special diet, comprising a mixture of flour, sugar, peptone, sub-nitrate of bismuth, and water or milk. The chemical, sub-nitrate of bismuth, was used in order to give the alimentary canal the necessary opacity to secure the best results under the Röntgen rays. In the case of the trout the chemical was injected into the blood.