142. Sciagraphs of Hair, Fur, etc., by TESLA, MORTON, and X-rays. Pulsation of Heat detected. and NORTON 142_a_. 143. Propagation of X-rays through Air to TESLA Distances of 60 ft. 144. X-rays with Moderate Vacuum and High TESLA Potential. 145. Detailed Construction and Use of Single TESLA Electrode Discharge Tubes for Generating X-rays. 146. Percentage of Reflection. TESLA and ROOD 146_a_. Reflected and Transmitted Rays TESLA Compared. Practical Application of Reflection in Sciagraphy. Analogy between Reflecting Power of Metals and their Position in the Electro-positive Series. 147. Discharge Tube Immersed in Oil. Rays TESLA Transmitted through Iron, Copper, and Brass, 1/4 in. Thick. 148. Bodies Not Made Conductors when Struck TESLA by X-rays. 149. Non-conductors Made Conductors by a APPLEYARD Current. 149_a_. Appleyard’s Experiment. Non-conductors Made Conductors by Current. 150. Electrical Resistance of Bodies Lowered MINCHIN by the Action of Electro-magnetic Waves. CHAPTER XII. 151. Sciagraphic Plates Combined with PUPIN, Fluorescent Salts. SWINTON, and HENRY. 152. Penetrating Power of X-rays Varies with THOMPSON, S. the Vacuum. P. 153. Reduction of Contact Potential of MURRAY Metals by X-rays. 154. Transparencies of Objects to X-rays Not NODON, Influenced by the Color. Detected by LUMIÈRE, Simultaneous Photographic BLEUNARD, and Impressions. LABESSE 155. Chlorine, Iodine, Sulphur, and MESLANS, Phosphorus Combined with Organic BLEUNARD, and Materials Increase Opacity. LABESSE 156. Application of X-rays to Distinguish BUQUET, Diamonds and Jet from Imitations. GASCARD, and THOMPSON, S. P. 157. Inactive Discharge Tubes Made Luminous DUFOUR by X-rays. 158. Non-refraction in a Vacuum. BEAULARD 159. Bas-relief Sciagraphs by X-rays. CARPENTIER and MILLER