On a whim, I did a search for the earliest appearance of Nikola Tesla's name in U.S. newspapers included in the NewspaperArchive.com* database. This story from Mr. George Grantham Bain appeared in multiple newspapers within a few days of this March 5, 1896 edition of The Warren Times in Warren, Pennsylvania, which coincidentally is only a few miles from me here in Erie. The article reports on the role that Tesla's high voltage generators played in the development of x-ray images on fluorescent displays and on film (which Tesla termed "cathode photography"). It mentions how the term "cathode" is relatively new to the general public even though it had been around since 1832 when Michael Faraday introduced it in his work. Wilhelm Röentgen made the world's first x-ray image - of his wife's hand! What the author called "wonderful cathode rays" had already been around for a whopping 15 years. The down side of early x-ray experimentation is that many men lost their hands and other body parts due to overexposure (NIH.gov).
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Professor Wilhelm Röentgen
Shadowgraph of Anna Roentgen' hand.
Development of Roentgen's Discovery.
Its Uses and Possibilities
Photographs Made Through Metals Two Years Ago.
Its Peculiar Properties Were All Set Forth to the Scientific World Early In 1894.
Not Much Better Understood Now Than It Was Then -
The Part Tesla's Converter Plays in Recent Experiments.
[Copyright, 1896, by the Author.]
New York, Feb. 28. - Probably no such popular furor for a purely scientific discovery was ever excited before us has grown out of the exploitation of the new photography with the aid of the X ray, or Roentgen ray, as it is popularly known.
How many intelligent and well educated men and women know, or knew a month ago, what a cathode is or was?
Yet the name cathode dates back to the time of Faraday, 1832.
The cathode ray has been known for more than 15 years.
Photography with the cathode ray is more than two years old.
In view of the excitement created all over the world by the experiments made by scientists in the last two months, these facts seem remarkable. They are beyond question, though, and I have seen the pictured results of cathode photography, the product of the experiments of Professor Philipp Lenard of Germany, published in March, 1894. Lenard's discoveries awakened the scientific world to investigation. Roentgen was one of the investigators. It happened to be the good fortune of Roentgen to discover the means of making a popular application of the discovery of Lenard and of Lenard's predecessors - Crookes, Hittorf and others. For this reason Roentgen is a popular hero and Lenard is ignored. But the scientific world gives Lenard the credit which is his due, and if he is not a person of narrow mind he is, no doubt, content with that.
Nikola Tesla, who believes he came very near a somewhat similar discovery, smiles when he speaks of the public excitement over the cathode photography and says everything will find its place when history is written. Mr. Tesla has a large interest even now in the development of the famous discovery, for the Tesla converter is used universally to produce those powerful rays with which Roentgen was able to accomplish what would have been impossible to Lenard without the Tesla apparatus. In fact, but for Tesla's invention there would have been no photographing of the bones of the hand. Lenard never got beyond the point of making the rays penetrate pieces of metal foil.
If you have ever been in a scientific class and studied electricity, you know the Leyden jar, with its brass knob, from which sparks of electricity pass when it is brought close to a conductor, provided the jar is charged. This is static electricity, or electricity which can be produced by ordinary friction. It was the first electricity known. Probably also you remember the tube in which electricity was made to pass from the positive to the negative pole of an interrupted circuit through a partial vacuum. The operation was accomplished with a brilliant display of colored lights, suggesting a fireworks show in miniature. The jar charged with static electricity and the vacuum tube are the foundation of the cathode photography. Faraday gave the title "anode" to the positive pole and "cathode" to the negative pole.
Between Hittorf and Crookes lies the credit of the discovery that from the cathode as well as from the anode in the vacuum tube proceeds a ray. For nearly half a century the cathode bad been apparently the receptacle, the anode the producer and disseminator, of light. In the brilliant rays which streamed from the positive pole the negative pole was thrown completely in shadow until Hittorf and Crookes almost simultaneously discovered that it, too, propagated a ray.
Crookes' achievements in the direction of producing a vacuum resulted in the Crookes tubes which have become famous popularly as well as scientifically of late because of their use in cathode photography. It was in one of his vacuum tubes that Crookes hunted down the cathode ray, or, as a recent scientific writer puts it, "vitalized" the ray for the benefit of the Royal society and the British association in 1879. In the scientific world the discovery was regarded as of grave importance, and the scientific journals made much of it. But if there was any mention of it in the daily or weekly newspapers it must have been very brief, and to the reader of unscientific mind must have seemed very uninteresting, for who, by the widest stretch of the imagination, could have associated the fact that a ray of some kind, imperceptible to the eye under ordinary conditions, proceeded from the negative pole of a Vacuum tube with the possibility of photographing the human brain? Certainly Crookes did not, and it was not until 1891 that the discovery was made that these peculiar rays would penetrate solids. Wiedemann and Ebert noticed in that year that gold leaf coatings on vacuum tubes were transparent to the cathode rays.
This fact, being made known to the scientific world, was developed by the late Professor Hertz, whose assistant was Professor Philipp Lenard. Professor Lenard became deeply interested in this peculiar property of the cathode ray and made earnest efforts to classify the ray, forming a theory that it was of etheric nature and basing his experiments on that idea. Up to the time of his experiments the rays had been studied only in the vacuum. The glass of the vacuum tube seemed impervious to them . Professor Lenard wanted to get them into the air. With other scientific men, he believed that they could not be led through glass, and he did not know that they would pass in to the air, but their ability to penetrate metal seemed to offer a means of leading them without the tube. Professor Hertz suggested the use of an aluminium window to bring the rays out, and this suggestion Professor Lenard adopted.
In the preparation of his apparatus for this important experiment - an experiment whose success now promises such remarkable scientific results - Professor Lenard sought to obtain a piece of aluminium foil which would be free from holes, but still not too thick to permit the passage of the rays, for he believed that the rays with which he was experimenting would not pass through any but a very thin piece of metal. The foil he selected was more than seven times the thickness of ordinary foil, (but still very light and thin. This foil he cemented across an opening 1 7-10 millimeters wide in a metal cap at the end of a vacuum tube. This tiny opening with its aluminium pane was the "window" through which the wonderful cathode ray was to reach the outer world, the first time in the history of modern science and probably in the world's history that it had been released from its airless birthplace. At the end of the vacuum tube opposite the aluminium window was introduced a brass tube, within this a glass tube of some thickness leading to an aluminium plate 12 millimeters in diameter. This glass tulle extended 12 millimeters beyond the brass tube. The aluminium plate was the cathode and the brass tube the anode of the experiment. They were connected by platinum wires with the poles of a galvanic battery. The whole apparatus was enclosed in a tin box.
It must have been with anxiety and a degree of nervous excitement that Professor Lenard set his battery in operation and started the rays from anode to cathode. The brilliant rays from the anode were imprisoned within the tube. They could not penetrate metal, though they could pass through glass. The cathode rays, imprisoned within the glass, passed through the aluminium window and made a faint glow in the dark room - mind, not a glow through the dark room, but in it, for their penetrating power was limited to five centimeters beyond the metal window. But they actually shone through the aluminium, through which no ray of light could possibly have passed. I don't know the exact date when this experiment was brought to its wonderful fruition, hut it was some time in 1893. Not once, but hundreds of times, was the peculiar ray made to shine through the metal window. Other apparatus was constructed, and it was made to shine through other metals. Its effect on phosphorescent bodies was determined, and its diffusion in the air was measured. Its diversion by the use of a magnet was a peculiar property demonstrated. And finally Professor Lenard took photographs with it on an ordinary dry plate.
What Nikola Tesla Discovered.
Nikola Tesla tells me he found some time ago that "when a strong, rapidly vibrating current passes through conductors there are propagated from them certain waves - 'sound waves of electrified air,' I called them. They are propagated in straight lines, like sound waves, and they penetrate bodies, and they cannot be stopped by interposing metal plates." lf it bad only occurred to Nikola Tesla to put a dry plate in the path of these "sound waves of electrified air," photography through opaque substances might have been known before, for Nikola Tesla tells me be has found that these "sound waves of electrified air" will make impressions on dry plates like the cathode rays.
But sound waves are not supposed to take photographs, and it would have been beyond all reason to expect it of them. The cathode rays illuminated very faintly, but perceptibly. It was natural for the experimenter to test their effect on the photographic plate and on sensitive paper for the purpose of creating an analogy between them and the rays of light which come to us as illuminants, but which, unlike the cathode rays, will not pass through opaque substances.
[From one of Roentgen's own negatives showing hand with rings on one finger.]
The cathode ray was not light, but it produced this one effect of light at least - it decomposed the chemicals on the dry plate. If the cathode waves would do this, why would not the "sound waves of electrified air?" The Roentgen experiments with the cathode rays showed that the rays were produced in unexampled strength by the use of the Tesla converter, through whose discharges the "electrified air" waves were produced. So Mr. Tesla very naturally tried the effect of his "sound waves of electrified air," with the result of which I have told. He was the first to photograph the human brain, and though he does not consider the photograph a success he expects to improve on it. In fact, he tells me he is progressing with his experiments rapidly to the point where he hopes to take instantaneous pictures with the new ray. Up to this time the best results have been obtained with exposures of an hour or more.
Lenard's experiments with the cathode ray stirred up the scientific world mightily. He not only demonstrated the possibility of bringing the new rays through metals, but brought them through glass. The glass was thin, though - thinner than had been used in prior experiments. Roentgen, as I have said, went one step beyond Lenard. He discovered a method of intensifying the ray so that it would pass through plates of metal as well as metal foil, through blocks of wood and other thick, opaque substances. This gave the discovery its practical value - its value in surgery and other fields, in which efforts are being made to apply it now. Roentgen is entitled to all credit for his development of the ray's uses. But before him others deserve some credit, and not the least among these is Nikola Tesla, whose converter is the medium through which all the successful results have been obtained.
The ray has not been classified yet. Lenard believes it is etheric. So does Roentgen. Tesla hopes it is a longitudinal sound wave. If it is etheric, he says, its sphere of usefulness is limited. It will probably never penetrate very great thicknesses. If it is a sound wave, it can go almost anywhere - through a brick wall or an iron safe.
Many Experimenters at Work.
Hundreds of American scientists are busily at work on the Lenard-Roentgen discovery. They regret that Tesla or Edison did not bring the credit of it to America, but they are no less enthusiastic on that account. They have determined that some good shall come out of America in connection with the discovery, and they are sitting up nights experimenting. If the exact nature of the ray could be determined, they could work more intelligently, but they are no worse off in this respect than are the scientists of Germany and England. So they are groping about, hoping in most cases that they may hit on something by accident. Edison began at the practical side of the business, as was natural. Demonstrations of new scientific facts appeal to Edison most when he can see some means of applying them to the work of man. So the first thing to which Edison turned his mind was the invention of some means of producing the new rays without the use of the expensive Crookes tube. Tesla began to work out a means of taking pictures instantaneously by the new photography, and he had been engaged in trying to classify the ray. Other scientists have devoted their attention especially to developing in the ray the refrangibleness of the ray of light. All have repeated the spectacular experiments made abroad - photographing the bones of the living hands, etc.
It would seem now to the unscientific mind as though two things were most immediately important - to concentrate the rays and increase their penetrating power. A third result to be attained by long and exhaustive experiments is to prove what substances are transparent to the rays and In what degree. But the American who proves the possibility of taking a direct photograph instead of a shadow photograph with the new rays will have his name linked with that of Lenard and Roentgen.
Now all that can be accomplished with the new photography is to cast the shadow of an opaque substance on the sensitive plate. When the cathode rays are propagated through the hand, they find the flesh and blood and skin transparent, but the bones are opaque. So the outline of the bones is traced on the sensitive plate. This has its value in surgery, and already bullets and other foreign substances have been located in men's hands by the new photography. But It will reach a higher stage of usefulness when the surface of the bone can be photographed through the flesh. Possibly before this written word sees type that wonder, too, will be developed.
Surgery seems likely to benefit most by the new science. It has been suggested that it can be used to detect flaws in metal plates. Edison and others have suggested that, as powerful rays of light, kill bacilli, the new ray might be a specific in some diseases. This seems fantastic, yet nothing would have seemed more fantastic to the mind of the average man a year ago than the suggestion that his skeleton could be photographed before he died.
Posted September 18, 2019