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
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
Faraday introduced it in his work.
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).
* Paid subscription required.
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
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 -
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
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
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