Vintage Medical Glass Slide Showing an X-ray of the Pelvic Bone and Lower Vertebrae

This is a Vintage Medical Glass Slide Showing an X-Ray of the Pelvic Bone and Lower Vertebrae, possibly produced for use in a magic lantern.  The slide measures 3.25" high by 4" wide and has edges bound with black paper which has been painted yellow.  The sides of the image have been masked with a black textured paper.  The back has a white label with an applied red star and the words "New 4*" written in black pen.  The image also includes what looks like a metallic bar with two screws on one side and the case numbers "103387 arrow R" and "11 29 32 P."  Maker and age are unknown.  This Vintage Medical Glass Slide Showing an X-Ray of the Pelvic Bone and Lower Vertebrae is in very good condition with only a tiny nick in the emulsion.  (Due to its fragility, this slide will be shipped in a box rather than in a padded envelope.)