CONTENTS.
CHAPTER I.
| [§ 1.] | Secondary Current by Induction. No Increased E. M. F. | Faraday |
| [2.] | Electric Spark and Increased E. M. F. by Induced Current. | Page |
| [3.] | Spark in Secondary Increased by Condenser in Primary. | Fizeau |
| [4.] | Atmosphere around an Incandescent Live Wire. | Vincintini |
| [5.] | Magnetizing Radiations from an Electric Spark. | Henry |
| [6.] | Arcing Metals at Low Voltage. | Faraday |
| [7.] | Non-arcing Metals at High Voltage. Practical Application. | Wurts |
| [8.] | Duration of Spark Measured. | Wheatstone |
| [8a.] | Discharge—Intermittent, Constant, and Oscillatory—by Variation of Resistance. | Feddersen |
| [9.] | Musical Note by Discharge with Small Ball Electrodes. Invisible Discharge. | Faraday |
| [9a]. | Pitch of Sound Changed by Approach of Conductor Connected to Earth. | Faraday and Mayer |
| [10.] | Brush Discharge. Color. Striæ. Nitrogen Best Transmitter of a Spark, and its Practical Bearing in Atmospheric Lightning. Cathode Brushes in Different Gases. | Faraday |
| [11.] | Glow by Discharge. Glow Changed to Spark. Motion of Air. Apparent Continuous Discharge during Glow. | Faraday |
| [12.] | Spark. Solids Perforated. | Lullin |
| [13.] | Spark. Glass Perforated. Holes Close Together. Practical Application for Porous Glass. | Fage |
| [14] and [14a.] | Spark. Penetrating Power. Conducting Power of Gas. Relation of E. M. F. to Pressure of Gases. Discharge through Hydrogen Vacuum Continued with Less Current than that Required to Start it. | Knochenhaurer, Boltzmann, Thomson (Kelvin), Maxwell, Varley, Harris, and Masson |
| [15.] | Dust Particles or Rust on the Electrodes Hasten Discharge. | Gordon |
| [16.] | Where the Distance is Greater, the Dielectric Strength is Smaller, Both Distances Being Minute. | Thomson (Kelvin) |
| [17.] | Discharge through Gases under Very High Pressures. Increased Dielectric Strength. | Cailletet |
| [18.] | Discharges in Different Chemical Gases Variably Resisted. | Faraday |
| [19.] | Gas as a Conductor. Molecule for Molecule, its Conductivity Greater than that for Gases. | Thomson, J. J. |
| [20.] | Relation of Light to Electricity. The Square Root of the Dielectric Capacity Equal to the Refractive Index. | Boltzmann, Gibson, Barclay, Hopkinson, and Gladstone |
| [21.] | Hermetically Sealed Discharge Tubes with Platinum Leading-in Wires. | Plücker and Geissler |
| [22.] | Luminosity of Discharge Tubes Produced by Rubbing. Increased by Low Temperature. | Geissler |
| [23.] | Different Vacua Needed for Luminosity by Friction and by Discharge. | Alvergniat |
| [24.] | Phenomena of Discharge around the Edges of an Insulating Sheet. | Steinmetz |
| [25.] | Highest Possible Vacuum Considered as a Non-conductor. | Morgan |
| [26.] | Constant Potential at the Terminals of a Discharge Tube. | De La Rue and Müller |
| [26a]. | Polarity of Discharge-tube Terminals in Secondary of Ruhmkorff Coil. Mathematical Deductions. | Klingenberg |
| [27.] | Pressure in Discharge Tube Produced by a Spark. | Kinnersley, Harris, and Riess |
CHAPTER II.
| [28.] | Actions of Magnetism upon the Arc and Flame. | Davy, Bancalari, and Quet |
| [29.] | Rotation of Luminous Discharge by a Magnet. Application in Explaining Aurora Borealis. | De La Rive |
| [30.] | Action of Magnet on the Cathode Light. Relations Different according to the Position Relatively to the Magnetic Lines of Force. | Plücker and Hittorf |
| [31.] | Discharge Retarded Across, and Accelerated Along, the Lines of Magnetic Force. | Thomson, J. J. |
| [32.] | Resistance of Luminosity of the Discharge Afforded by a Thin Diaphragm. | Thomson, J. J. |
| [33.] | Forcing Effect of the Striæ at a Perforated Diaphragm. | Solomons |
CHAPTER III.
| [34.] | Electric Images. | Riess |
| [35.] | Electrographs on Photographic Plate by Discharge. | Sanford and McKay |
| [36.] | Positive and Negative Dust Pictures upon Lines Drawn by Electrodes. | Lichtenberg |
| [36a.] | Photo-electric Dust Figures. | Hammer |
| [36b.] | Dust Portrait. | Hammer |
| [37.] | Electrical Images by Discharge Developed by Condensed Moisture. | Karsten |
| [37a.] | Magnetographs. | McKay |
| [38.] | Bas-relief Facsimiles by Electric Discharge. | Piltchikoff |
| [39.] | Distillation of Liquids by Discharge. | Gernez |
| [40.] | Striæ. Black Prints on Walls of Tube. | De La Rue and Müller |
CHAPTER IV.
| [41.] | Discharge Tube in Primary Current. Striæ. Least E. M. F. Required. | Gassiot |
| [42.] | Current Interrupted Inside of Discharge Tube instead of Outside. | Poggendorff |
| [43.] | Source of Striæ at the Anode. Color Changed by Change of Current. | De La Rue and Müller |
| [44.] | Dark Bands by Small Discharges Disappear on Increase of Current, and Appear Again by Further Increase. | Solomons |
| [45.] | Motion of Striæ. Method of Obtaining Motion when Desired and of Stopping the Same. | Spottiswoode |
| [46.] | Motion of Striæ Checked at the Cathode. Tube, 50 ft. Long. The Anode the Starting-point. | Thomson, J. J. |
| [47.] | Electrolysis in Discharge Tube. | Thomson, J. J. |
| [48.] | Heat Striæ without Luminous Striæ. | De La Rue and Müller |
| [49.] | Sensitive State. Method of Obtaining. Telephone Used to Prove Intermissions. | Spottiswoode and Moulton |
| [49a.] | Cause of Sensitive State Detected by Telephone. | Spottiswoode and Moulton |
| [50.] | Sensitive State Illustrated by a Flexible Conductor within the Discharge Tube. | Reitlinger and Urbanitzky |
| [51.] | System of Operating Discharge Tubes. Excessively High Potential and Enormous Frequency. | Tesla |
| [52.] | Discharge-tube Phenomena by Self-induced Currents. | Moore |
CHAPTER V.
| [53.] | Dark Space around the Cathode. | Crookes |
| [54.] | Relation of Vacuum to Phosphorescence. | Crookes |
| [55.] | Phosphorescence of Objects within Discharge Tube. | Crookes |
| [56.] | Darkness and Luminosity in the Arms of a V Tube. | Crookes |
| [57.] | Cathode Rays Rectilinear within the Discharge Tube. | Crookes |
| [58.] | Shadow Cast within the Discharge Tube. | Crookes |
| [58a.] | Mechanical Force of Cathode Rays. Wheel Caused to Rotate. | Crookes |
| [59.] | Action of Magnet upon Cathode Rays in Discharge Tube. | Crookes |
| [60.] | Mutual Repulsion of Cathode Rays in Discharge Tube. | Crookes |
| [61.] | Heat of Phosphorescent Spot. | Crookes |
| [61a]. | Theoretical Considerations of Thomson (Kelvin). | |
| [61b], page [46]. | Velocity of Cathode Rays. | Thomson, J. J. |
| [61b], page [47]. | Cathode Rays Charged with Negative Electricity. | Perrin |
| [61c], | Zeugen’s Photograph of Mt. Blanc Not Due to Cathode Rays. | |
| [62.] | Phosphorescence of Particular Chemicals by Cathode Rays. | Goldstein |
| [63.] | Spectrum of Post-phosphorescence of Discharge Tube Compared with that of Red-hot Metals. | Kirn |
| [63a.] | Chemical Action on Photographic Plate by Cathode Rays Inside of Discharge Tube. | De Metz |
| [63b.] | The Passage of Cathode Rays through Thin Metal Plates within the Discharge Tube (no. § 64). | Hertz |
CHAPTER VI
| [§ 65], top of page [53]. | Cathode Rays Outside of the Discharge Tube whose Exit is an Aluminum Window. A Glow Outside of the Window. | Lenard |
| [65.], end of page [53]. | Properties of Cathode Rays in Open Air. | Lenard |
| [66.] | Phosphorescence by Cathode Rays Outside of the Discharge Tube. | Lenard |
| [66a]. | Transmission Tested by Phosphorescence. | |
| [67.] | The Aluminum Window a Diffuser of Cathode Rays. | Lenard |
| [68.] | Transmission of External Cathode Rays through Aluminum and Thinly Blown Glass. | Lenard |
| [69.] | Propagation of External Cathode Rays. Turbidity of Air. | Lenard |
| [70.] | Photographic Action by External Cathode Rays and at Points beyond the Glow. No Other Chemical Power Probable. Shadows of Objects by Light and by External Cathode Rays Compared. No Heat Produced by External Cathode Rays. | Lenard |
| [71.] | External Cathode Rays and the Electric Spark Distinguished. Aluminum Window Not a Secondary Cathode. | Lenard |
| [72.] | Cathode Rays Propagated, but Not Generated, in the Highest Possible Vacuum. Air Less Turbid when Rarefied. | Lenard |
| [72a]. | Cathode Rays, while Traversing the Exhausted Observing Tube, Deflected by a Magnet. No Turbidity in a Very High Vacuum. | Lenard |
| [72b]. | An Observing Tube for Receiving the Rays and Adapted to be Exhausted. | Lenard |
| [73.] | Phenomena of Cathode Rays in an Observing Tube Containing Successively Different Gases at Different Pressures. Phosphorescent Screen Employed for Making the Test. | Lenard |
| [74.] | Cause of the Glow Outside of the Aluminum Window. Glow Not Caused by External Cathode Rays. Sparks Drawn from the Aluminum Window. Transmission of External Cathode Rays Dependent Alone upon the Density of the Medium. | Lenard |
| [75.] | External Cathode Rays of Different Kinds Variably Diffused. Theoretical Observations. | Lenard |
| [76.] | Law of Propagation of External Cathode Rays. | Lenard |
| [77.] | Charged Bodies Discharged by External Cathode Rays. Discharge at Greater Distances than Phosphorescence. Not Certain as to the Discharge Being Directly Due to Intermediate Air. | Lenard |
| [78.] | Source, Propagation, and Direction of Cathode Rays. General Conclusions. | De Kowalskie |
CHAPTER VII.
| [79.] | X-rays Uninfluenced by a Magnet. Source of X-rays Determined by Magnetic Transposition of Phosphorescent Spot. | Roentgen |
| [80.] | Source of X-rays may be at Points within the Vacuum Space. Different Materials Radiate Different Quantities of X-rays. | Roentgen |
| [81.] | Reflection of X-rays. | Roentgen |
| [82.] | Examples of Penetrating Power of X-rays. | Roentgen |
| [83.] | Permeability of Solids to X-rays Increases Much More Rapidly than the Thickness Decreases. | Roentgen |
| [84.] | X-rays Characterized. Fluorescence and Chemical Action. | Roentgen |
| [85.] | Non-refraction of X-rays Determined by Opaque and Other Prisms. Refraction, if Any, Exceedingly Slight. | Roentgen |
| [86.] | Velocity of X-rays Inferred to be the Same in All Bodies. | Roentgen |
| [87.] | Non-double Refraction Proved by Iceland Spar and Other Materials. | Roentgen and Mayer |
| [88.] | Rectilinear Propagation of X-rays Indicated by Pin-hole Camera and Sharpness of Sciagraphs. | Roentgen |
| [89.] | Interference Uncertain Because X-rays Tested were Weak. | Roentgen |
| [90.] | Electrified Bodies, whether Conductors or Insulators, or Positive or Negative, Discharged by X-rays. Hydrogen, etc., as the Intermediate Agency. | Roentgen |
| [90a.] | Application of Principle of Discharge by X-rays. | Roentgen |
| [90A,] [b,] [c,] [d.] | Supplementary Experiments on Charge and Discharge by X-rays. | Minchin, Righi, Benoist, Hurmuzescu, and Borgmann |
| [91.] | Focus Tube. | Roentgen, Shallenberger, et al. |
| [91a.] | Tribute to the Tesla Apparatus. | Roentgen |
| [92.] | X-rays and Longitudinal Vibrations. | Roentgen |
| [93.] | Longitudinal Waves in Luminiferous Ether by Electrical Means Early Predicted by | Thomson (Kelvin) |
| [94.] | Theory as to X-rays Being of a Different Order of Magnitude from those so far Known. | Schuster |
| [95.] | Longitudinal Waves Exist in a Medium Containing Charged Ions. Theoretical. | Thomson, J. J. |
| [96.] | Practical Application of X-rays Foreshadowed. | Boltzmann |
| [97.] | The Sciascope. | Magie, Salvioni, et al. |
CHAPTER VIII.
| [97a.] | Electrified Bodies Discharged by Light of a Spark, and the Establishment of a Radical Discovery. | Hertz |
| [97b]. | Above Results Confirmed and More Specific Tests. | Wiedemann and Ebert |
| [98.] | Negatively Charged Bodies Discharged by Light. Discharge from Earth’s Surface Explained by Inference and Experiment. | Elster and Geitel |
| [99.] | Relation between Light and Electricity. Cathode of Discharge Tube Acted upon by Polarized Light and Apparently Made a Conductor Because of the Discharging Effect. | Elster and Geitel |
| [99A] to [99T.] | Briefs Regarding Action between Electric Charge and Light. | Schuster, Righi, Stolstow, Branly, Borgmann, Mebius, et al. |
CHAPTER IX.
| [100.] | Stereoscopic Sciagraphs. | Thomson, E. |
| [101.] | Obtaining Manifold Sciagraphs Simultaneously upon Superposed Photographic Films and through Opaque Materials, and thus Indicating Relative Sensitiveness of Different Films to X-rays. Intensifying Process Applicable in Sciagraphy. Thick Films Appropriate. | Thomson, E. |
| [101a.] | Sciagraph Produced through 150 Sheets of Photographic Paper. | Lumière. |
| [102.] | Discharge Tube Adapted for Both Unidirectional and Alternating Currents. | Thomson, E., and Swinton |
| [103.] | X-rays. Opalescence and Diffusion. | Thomson, E., Pupin, and Lafay |
| [103a.] | Diffusion and Reflection in Relation to Polish. | Imbert, et al. |
| [104.] | Fluorometer. Fluorescing Power of Different Discharge Tubes Compared. | Thomson, E. |
| [105.] | Modified Sciascope for Locating the Source and Direction of X-rays. Phosphorescence Not an Essential Accompaniment in Production of X-rays. | Thomson, E. |
| [106.] | X-rays from Discharge Tube Excited by Wimshurst Machine. Full Details Given of the Electrical Features. | Rice, Pupin, and Morton |
| [107.] | Source of X-rays Determined by Projection through a Small Hole upon Fluorescent Screen Adjustable to Different Positions. | Rice |
| [107a.] | Use of Stops in Sciagraphy. | Leeds and Stokes |
| [107b.] | X-rays from Two Phosphorescent Spots. | Macfarlane, Klink, Webb, Clark, Jones, and Morton |
| [108.] | Source of X-rays Determined by Shadows of Short Tubes. | Stine |
| [109.] | Instructions Concerning Electrical Apparatus for Generating X-rays. | Stine |
| [110.] | Apparent Diffraction Really Due to Penumbral Shadows. | Stine |
| [110a]. | Non-diffraction. | Perrin |
| [159a]. | Non-Refraction | |
| [111.] | Source of X-rays Tested by Interceptance of Assumed Rectilinear Rays from the Cathode. | Scribner and M’Berty |
| [112.] | Source of X-rays on the Inner Surface of the Glass Tube Determined by Pin-hole Images. | Scribner and M’Berty, Perrin |
| [112a]. | Anode Thought to be the Source. Cause of Error Suggested. | De Heen |
| [113.] | Pin-hole Pictures by X-rays Compared with Pin-hole Images by Light to Determine the Source. X-rays Most Powerful when the Anode is the Part Struck by the Cathode Rays. | Lodge |
| [114.] | Valuable Points Concerning Electrical Apparatus Employed. | Lodge |
| [115.] | X-rays Equally Strong during Fatigue of Glass by Phosphorescence. | Lodge |
| [116.] | Area Struck by Cathode Rays Only an Efficient Source when Positively Electrified. | Rowland, Carmichael, and Briggs |
| [117.] | Transposition of Phosphorescent Spot and of Cathode Rays without a Magnet. | Salvioni, Elster, Geitel, and Tesla |
| [117a.] | Molecular Sciagraphs in a Vacuum Tube. | Hammer and Fleming |
CHAPTER X.
| [118.] | X-rays Begin before Striæ End. | Edison and Thomson, E. |
| [119.] | Reason why Thin Walls are Better than Thick. | Edison |
| [120.] | To Prevent Puncture of Discharge Tube by Spark. | Edison |
| [121.] | Variation of Vacuum by Discharge and by Rest. | Edison |
| [122.] | External Electrodes Cause Discharge through a Higher Vacuum than Internal. | Edison |
| [123.] | Profuse Invisible Deposit from Aluminum Cathode. | Edison and Miller |
| [124.] | Possible Application of X-rays. Fluorescent Lamp. | Edison and Ferranti |
| [124a.] | Greater (?) Emission of X-rays by Easily Phosphorescent Materials. | Piltchikoff |
| [125.] | Electrodes of Carborundum. | Edison |
| [126.] | Chemical Decomposition of the Glass of the Discharge Tube Detected by the Spectroscope. | Edison |
| [127.] | Sciagraphs. Duration of Exposure Dependent upon Distances. | Edison |
| [128.] | Differences between X-rays and Light Illustrated by Different Photographic Plates. Times of Exposure. | Edison, Frost, Chappin, Imbert, Bertin-Sans, and Meslin |
| [128a.] | Georges Meslins insured a reduction of time for taking sciagraphs by the deflection of the cathode rays by means of a magnetic field | |
| [129.] | Size of Discharge Tube to Employ for Given Apparatus. | Edison |
| [130.] | Preventing Puncture at the Phosphorescent Spot. | Edison |
| [131.] | Instruction Regarding the Electrical Apparatus. | Edison and Pupin |
| [132.] | Salts Fluorescent by X-rays. 1800 Chemicals Tested. | Edison |
| [133.] | X-rays Apparently Passed around a Corner. Theoretical Consideration by Himself and Others. | Edison, Elihu Thomson, Anthony, et al. |
| [134.] | Permeability of Different Substances to X-rays. A List of a Variety of Materials. | Edison and Terry |
| [134a.] | Illustration of Penetrating Power of Light. | Hodges |
| [135.] | Penetrating Power of X-rays Increased by Reduction of Temperature. Tube Immersed in Oil, and the Oil Vessel in Ice. X-rays Transmitted through Steel 1/8 in. Thick. | Edison |
| [136.] | X-rays Not Obtainable from Other Sources than Discharge Tube. | Edison, Rowland, et al. |
CHAPTER XI.
| [137.] | Kind of Electrical Apparatus for Operating Discharge Tube for Powerful X-rays. | Tesla and Shallenberger |
| [138.] | How to Maintain the Phosphorescent Spot Cool. | Tesla |
| [139.] | Expulsion of Material Particles through the Walls of a Discharge Tube. | Tesla |
| [139a.] | Giving to X-rays the Property of Being Deflected by a Magnet. | Lafay and Lodge |
| [139b.] | Penetration of Molecules into the Glass of the Discharge Tube. | Gouy |
| [140.] | Vacuum Tubes Surrounded by a Violet Halo. | Tesla and Hammer |
| [141.] | Anæsthetic Properties of X-rays. | Tesla and Edison |
| [142.] and [142a]. | Sciagraphs of Hair, Fur, etc., by X-rays. Pulsation of Heat detected. | Tesla, Morton, and Norton |
| [143.] | Propagation of X-rays through Air to Distances of 60 ft. | Tesla |
| [144.] | X-rays with Moderate Vacuum and High Potential. | Tesla |
| [145.] | Detailed Construction and Use of Single Electrode Discharge Tubes for Generating X-rays. | Tesla |
| [146.] | Percentage of Reflection. | Tesla and Rood |
| [146a.] | Reflected and Transmitted Rays Compared. Practical Application of Reflection in Sciagraphy. Analogy between Reflecting Power of Metals and their Position in the Electro-positive Series. | Tesla |
| [147.] | Discharge Tube Immersed in Oil. Rays Transmitted through Iron, Copper, and Brass, 1/4 in. Thick. | Tesla |
| [148.] | Bodies Not Made Conductors when Struck by X-rays. | Tesla |
| [149.] | Non-conductors Made Conductors by a Current. | Appleyard |
| [149a.] | Appleyard’s Experiment. Non-conductors Made Conductors by Current. | |
| [150.] | Electrical Resistance of Bodies Lowered by the Action of Electro-magnetic Waves. | Minchin |
CHAPTER XII.
| [151.] | Sciagraphic Plates Combined with Fluorescent Salts. | Pupin, Swinton, and Henry. |
| [152.] | Penetrating Power of X-rays Varies with the Vacuum. | Thompson, S. P. |
| [153.] | Reduction of Contact Potential of Metals by X-rays. | Murray |
| [154.] | Transparencies of Objects to X-rays Not Influenced by the Color. Detected by Simultaneous Photographic Impressions. | Nodon, Lumière, Bleunard, and Labesse |
| [155.] | Chlorine, Iodine, Sulphur, and Phosphorus Combined with Organic Materials Increase Opacity. | Meslans, Bleunard, and Labesse |
| [156.] | Application of X-rays to Distinguish Diamonds and Jet from Imitations. | Buquet, Gascard, and Thompson, S. P. |
| [157.] | Inactive Discharge Tubes Made Luminous by X-rays. | Dufour |
| [158.] | Non-refraction in a Vacuum. | Beaulard |
| [159.] | Bas-relief Sciagraphs by X-rays. | Carpentier and Miller |
| [160.] | Transparency of Eye Determined by Sciagraph of Bullet Therein. | Wuillomenet |
| [161.] | Mineral Substances Detected in Vegetable and Animal Products. | Ranwez |
| [162.] | Hertz Waves and Roentgen Rays Not Identical. | Errera |
| [163.] | Non-mechanical Action by X-rays Determined by the Radiometer. | Gossart |
| [164.] | X-rays within Discharge Tube. | Battelli |
| [165.] | Combined Camera and Sciascope. | Bleyer |
| [166.] | Non-polarization of X-rays. | Thompson, S. P., Macintyre |
| [167.] | Diffuse Reflection. Dust Figures Indirectly by X-rays. | Thompson, S. P. |
| [168.] | Continuation of Experiments in [§ 113]. | Lodge |
| [169.] | Thermopile Inert to X-rays. | Porter |
| [170.] | Non-diffraction of X-rays. | Magie |
| [171.] | Resistance of Selenium Reduced by X-rays. | Giltay and Haga |
Total number of sections to this place, 199.
CHAPTER XIII.
| [200.] | Needle Located by X-rays and then Removed. | Hogarth |
| [201.] | Needle Located at Scalpel by X-rays and then Removed. | Savary |
| [202.] | Diagnosis with Fluorescent Screen. | Renton and Somerville |
| [203.] | Bullet Located by Five Sciagraphs. | Miller |
| [204.] | Bones in Apposition Discovered by X-rays and afterward Remedied by Operation. Other Cases. | Miller |
| [204a.] | Necrosis. | Miller |
| [205.] | Application of X-rays in Dentistry. | Morton |
| [206.] | Elements of the Thorax. | Morton |
| [207.] | A Colles’ Fracture Detected by X-rays. | Morton |
| [208.] | Motions of Liver, Outlines of Spleen, and Tuberculosis Indicated. | Morton and Williams |
| [209.] | Osteomyelitis distinguished from Periostitis. | Lannelongue, Barthelemy, and Oudin. |
| [210.] | Concluding Miscellaneous Experiments Relating to Similar Applications of X-rays. | Ashhurst, Packard, Müller, Keen, and Morton, T. G. |
CHAPTER XIV.
| [Theoretical Considerations], Arguments, and Kindred Radiations. | Anthony |