CHAPTER VII.

79. X-rays Uninfluenced by a Magnet. Source ROENTGEN of X-rays Determined by Magnetic Transposition of Phosphorescent Spot.

80. Source of X-rays may be at Points ROENTGEN within the Vacuum Space. Different Materials Radiate Different Quantities of X-rays.

81. Reflection of X-rays. ROENTGEN

82. Examples of Penetrating Power of ROENTGEN X-rays.

83. Permeability of Solids to X-rays ROENTGEN Increases Much More Rapidly than the Thickness Decreases.

84. X-rays Characterized. Fluorescence and ROENTGEN Chemical Action.

85. Non-refraction of X-rays Determined by ROENTGEN Opaque and Other Prisms. Refraction, if Any, Exceedingly Slight.

86. Velocity of X-rays Inferred to be the ROENTGEN Same in All Bodies.

87. Non-double Refraction Proved by Iceland ROENTGEN and Spar and Other Materials. MAYER

88. Rectilinear Propagation of X-rays ROENTGEN Indicated by Pin-hole Camera and Sharpness of Sciagraphs.

89. Interference Uncertain Because X-rays ROENTGEN Tested were Weak.

90. Electrified Bodies, whether Conductors ROENTGEN or Insulators, or Positive or Negative, Discharged by X-rays. Hydrogen, etc., as the Intermediate Agency.

90_a_. Application of Principle of Discharge ROENTGEN by X-rays.

90_A_, Supplementary Experiments on Charge and MINCHIN, _b_, Discharge by X-rays. RIGHI, _c_, BENOIST, _d_. HURMUZESCU, and BORGMANN

91. Focus Tube. ROENTGEN, SHALLENBERGER, _et al._

91_a_. Tribute to the Tesla Apparatus. ROENTGEN

92. X-rays and Longitudinal Vibrations. ROENTGEN

93. Longitudinal Waves in Luminiferous THOMSON Ether by Electrical Means Early (KELVIN) Predicted by

94. Theory as to X-rays Being of a SCHUSTER Different Order of Magnitude from those so far Known.

95. Longitudinal Waves Exist in a Medium THOMSON, J. J. Containing Charged Ions. Theoretical.

96. Practical Application of X-rays BOLTZMANN Foreshadowed.

97. The Sciascope. MAGIE, SALVIONI, _et al._