TY - JOUR T1 - The Production of X Rays of Different Penetrative Values JF - Proceedings of the Royal Society of London (1854-1905) VL - 61 SP - 222 EP - 226 PY - 1897/01/01/ UR - http://dx.doi.org/10.1098/rspl.1897.0026 M3 - doi:10.1098/rspl.1897.0026 AU - Swinton, A. ER -