X-ray

“ Close began a series of treatments with an X-ray specialist in New York,” pursued Kennedy. “Now, it is not generally known outside scientific circles, but the fact is that in their physiological effects the X-ray and radium are quite one and the same. Radium possesses this advantage, however, that no elaborate apparatus is necessary for its use. And, in addition, the emanation from radium is steady and constant, whereas the X-ray at best varies slightly with changing conditions of the current and vacuum in the X-ray tube. Still, the effects on the body are much the same. ”

“ Many persons confuse the greenish light from an X-ray tube with the X-rays, but the two are actually entirely different manifestations. The X-rays, though invisible to the eye, are nevertheless able to affect a photographic plate strongly, so that photographs may be made through solid objects. For example, if a sensitive plate be laid on a table and the arm or the hand placed on it, and an X-ray tube is brought near the arm, a photograph results in which the bone is represented as a dark area and the flesh around it as lighter, this being, of course, simply a shadow picture. ”

“ The X-rays are also used to determine the quality of the fabric in automobile tires, and even to detect irregularities in the centers of golf balls, and to reveal why some of them fly straighter and farther than others. ”

“ Highly important as are the phenomena of Radioactivity from the physical, chemical, medical, and philosophic points of view, they are hardly comparable in their relations to the affairs of our everyday life to the Roentgen or X-rays, and to the invisible violet or ultra-violet rays. The X-rays are utilized today in hundreds of practical ways, and are vastly important also in surgery, medicine, dentistry, and in biological investigations. ”

“ Can it be that all the skill and industry which has been employed to perfect X-ray apparatus is to be supplanted by a powder? The peculiar property shown by the radio-active substances leads investigators to surmise that we have evidence of new substances, and we have the waves radium and polonium.
The methods by which the X rays are detected in practical employment in surgery have not been essentially changed. ”

“ Of course an X-ray tube operates in accordance with the electron theory, but it shoots the electrons off—it doesn’t throw them out as an electromagnetic field of force, which is probably the fashion in which our earthly radio waves are propagated. In other words, although I was still using the electrons in my work, I had an entirely new type of receiving set, and one which, although it might not actually hear messages from another planet, would perhaps be the stepping stone on which some future inventor might build success. ”

“ As radiography is most likely to be taken up by photographers, it may be well to state here that any photographic plates or papers240 left in their usual wrappings in the room in which X-rays are being produced are almost certain to be spoiled, and they should be placed in a tightly fitting metal box or be taken into the next room. It is not necessary for the amateur doing only occasional X-ray work with small apparatus to take any of the precautions mentioned in the previous paragraph, for there is not the slightest danger in such work. ”

“ As is well known, it is not difficult to make an X-ray picture of the bones of the body. They are so much denser than the soft parts of the body that, even with the ordinary photographic plate, it has been possible to photograph them fairly well. By pumping the stomach full of gas or air—which are highly transparent to the [Pg 22] X-rays—and then applying the X-ray, it has sometimes been possible to locate the beginnings of cancer of the stomach, and the place of malignant growth. ”

“ With the lead-glass bowl removed, the X-ray tube sent forth its wonderful invisible radiation and made the back of the fluoroscope glow with light. I could see the bones of my fingers as I held them up between the X-ray tube and the fluoroscope. But with the lead-glass bowl in position over the tube, the fluoroscope was simply a black box into which I looked and saw nothing. ”

“ Although the X-rays are left to your imagination, the photograph at any rate shows the process of ionization which is so important in the stellar interior—the freeing of electrons from the atoms by the incidence of X-rays. You notice that it is just a chance whether the X-ray ionizes an atom when it meets it. There are trillions of atoms lying about (of which the photograph takes no notice) ; but, nevertheless, the X-rays travel a long way before meeting the atom which they choose to operate on. ”

“ In extreme cases the X-rays may cause complete destruction of the skin and even cancer, and before the properties of the X-rays were so well known as at present many operators lost hands, and some their lives, as a result of excessive exposure to the rays. At present, X-ray workers shield themselves, and, when necessary, the patient, with lead screens, that metal being practically opaque to the rays. ”

“ The X-Ray enables us to see through solid bodies. Radium, which has no appearance of light, will affect a photographic plate through a foot of iron. Actinium, one of the radioactive substances, is said to have a chemical activity which is about a thousand million times swifter than that of radium. ”

“ I have told you that under certain circumstances a stream of electrons may generate X-Rays, in reality a form of light rays. This action is a very common one, and it is curious that the faster the electron goes the shorter is the wave-length of the radiation. A very fast electron generates an X-Ray of so short a wave-length that the penetrating power of the ray, which goes with the shortness of the wave, is excessive, and in this way we may have rays which go right through the human body or even through inches of steel. ”

“ The X-rays that are being used to cure a patient may at the same time inflict radio-dermatitis on other persons exposed to their influence in adjoining rooms or buildings. Nothing will suffice for safety but to cover the walls and floors of X-ray rooms with sheets of lead from a quarter to half an inch thick, according to the power of the source and its distance from the lining....
“Biologic reactions from X-rays take two forms. The first is a skin lesion known as radio-dermatitis, caused by the skin’s absorbing a large quantity of radiations. ”

“ The wonderful X-ray, and the rich scientific harvest which has followed the discovery by Röntgen of invisible radiation from a vacuum tube, was preceded by much investigation of the effects of electric discharges in vacuum tubes, and Hittorf, followed by Crookes, had given special study to these effects in very high or nearly perfect vacua. Crookes, though especially enriching science by his work, missed the peculiar X-ray, which, nevertheless, must have been emitted from many of his vacuum tubes, not only in his hands, but in those of subsequent students. ”

“ It has been found that actively growing tissue, whether normal or pathological, is the most susceptible to X-rays, and it is comparatively easy to sterilize a number of species of animals without otherwise injuring them. ”

“ X-rays constitute the only sure way to tell good eggs from bad. Pass each egg in turn through the X-rays and let its shadow fall on a chemical screen. You will see exactly what is inside each egg. The [Pg 9] ones containing hopeful chicks may be rejected.”
One of the most remarkable economic or biological uses of the X-ray so far developed is the study of silk-worms and their diseases. The Silk Association of America has established a laboratory—Department of Sericulture—in the Canton Christian College, presided over by a staff of Chinese and foreign entomologists. ”

“ Every crystal has its characteristic X-ray spectrum and can be identified thereby even when the individual crystals are beyond the resolving power of the microscope and the substance is in danger of being called amorphous. ”

“ They are allowed to fall (still invisible) on to a photographic plate, when a picture like an ordinary permanent photograph is obtained by their chemical action, or they may be made to exert their phosphorescence-producing power on a glass plate covered with a thin coating of a phosphorescent salt such as barium platino-cyanide, when a temporary picture in light and shade is seen.
The rays discovered by Röntgen were known as the X-rays, because their exact nature was unknown. ”

“ But this property of X-rays introduces a serious difficulty into the ether theory. For if the electric intensity in the wave front of the X-ray is sufficient thus to hurl a corpuscle with huge energy from one particular atom, why does it not at least detach corpuscles from all of the atoms over which it passes?
Again when ultra-violet light falls on a metal it, too, like X-rays, is found to eject negative electrons. This phenomenon of the emission of electrons under the influence of light is called the photo-electric [Pg 236] effect. ”

“ More elaborate is examination under various rays of the spectrum, to which the human eye is not sensitive but whose results can be recorded. The best known of these is X-ray, which penetrates certain substances but is held up in different degrees by others, especially metals, so that a photographic film behind an object will record a map of such substances in an object, thus revealing much 22 that is below the surface. On the other hand, ultra-violet rays falling on a surface cause fluorescence, which varies according to substance and texture, so that additions to the surface may be revealed. ”

“ Even those medical men whose interest is entirely commercial appreciate the convenience of the X-ray and the importance of correctly interpreting the pathological effects of the rays of radio-activity and ultra-violet light. One finds a great geologist in collaboration with his distinguished colleague in physics, and from the latter comes a contribution on the rigidity of the earth. Astronomy answers nowadays to the name of astrophysics, and progressive observatories recognize in the laboratory a tool as essential as the telescope. ”

“ Geissler Tubes—Vacuum Tubes of Crookes, Hittorf and Lenard—The Cathode Ray—Roentgen’s Great Discovery in 1895—X-Ray Apparatus—Salvioni’s Cryptoscope—Edison’s Fluoroscope—The Fluorometer—Sun Burn from X-Rays—Uses of X-Rays.
The majority of people have been accustomed to regard light as something to be excluded and controlled by opaque screens just as effectively as rain is excluded by a tin roof, or cold is kept out by a brick wall. ”

“ Down in a lower compartment there seems to be an orthodox receiving set with eight oversize tubes. All the wiring is oversize, too, and so are the transformers. Up above the set there are a lot of little control appliances, evidently of your own invention, and the biggest X-ray tube I’ve ever seen, with some sort of a focusing device pointed down into the lower compartment. ”

“ And I also know that you are one of the most careful X-ray operators in the city. If this suit goes against you, one of the most brilliant men of science in America will be ruined. Now, having said this much, let me ask you to describe just exactly what treatments you gave Mrs. Close."
The doctor led us into his X-ray room adjoining. A number of X-ray tubes were neatly put away in a great glass case, and at one end of the room was an operating-table with an X-ray apparatus suspended over it. A glance at the room showed that Kennedy's praise was not exaggerated. ”

“ Probably in no other condition, unless it be in fractured bones, has the X-ray proved itself of so much value as in the location of foreign bodies lodged in any of the organs or tissues of the body. Before Professor Röntgen’s discovery it was not of infrequent occurrence that an exploratory operation was necessary to positively prove the presence of a foreign body, and even this was at times of necessity a failure. To-day the X-ray picture enables the surgeon to learn the exact location of the foreign body and indicates to him the best point from which it may be attacked. ”

“ The modern X-ray photographs very crudely reveal the internal structure of certain solid objects; but a trained student of anatomy of the brain has largely symbolic ideas of its structure which far exceed, in value of their correspondence to their object, all that can ever be hoped for from the X-ray photographs of a brain. In general, the photograph gives us at its best very one-sided ideas of visible objects. ”

“ When ultra-violet light is allowed to fall upon a metal it causes the metal to emit electrons and thus to acquire a positive charge, the velocity of the emitted electrons being exactly proportional to the frequency of the incident light. Or when light of X-ray type falls upon the surface of almost any substance, it takes hold of an electron in the atoms of that surface and hurls it out into space with a speed exactly proportional to the wave length of the light. ”

“ Three per cent of the conveniences—the public X-ray machines for keeping people from being fooled about themselves will be enough.
The minute we begin turning the X-ray outfit around and begin trying it modestly on ourselves, a small cheap outfit will do. ”

“ Edison says with regard to this work: "When the X-ray came up, I made the first fluoroscope, using tungstate of calcium. I also found that this tungstate could be put into a vacuum chamber of glass and fused to the inner walls of the chamber; and if the X-ray electrodes were let into the glass chamber and a proper vacuum was attained, you could get a fluorescent lamp of several candle-power. I started in to make a number of these lamps, but I soon found that the X-ray had affected poisonously my assistant, Mr. Dally, so that his hair came out and his flesh commenced to ulcerate. ”