A Simple Optical Appliance for Use with Respirators.

Conclusions emerging from this experiment are as follows. (1) That most kinds of glass in common use are opaque to X-rays. (2) That small fiagments of the order of i-2 mm. in thickness show an opacity when exposed through the thickness of the eye and eyelids, and in addition through the thickness of the skull, but that fragments of under 1 mm. in thickness may be difficult of detection in such conditions. (3) It may be concluded that pieces of glass actually in the eye or orbit and exposed to X-rays under comparable conditions would also show, but that having regard to the somewhat greater distance of the foreign particles from the film in such a case, fragments of under 1 mm. in thickness would a fortiori, be difficult of detection.