If you break your arm or leg, the doctor will probably send you to hospital to have an X-ray photograph taken to
 find out just where the break is and what kind of break it is.
如果你断了手臂或腿，医生可能会送你到医院去照Ｘ光，看看是那里折断了，以及是那一种折断。
If a small child swallows a coin or some other hard thing, as sometimes happens, the doctor will take an X-ray
 photograph to find out just where the object has got to in the child's body.
如果一个小孩吞下了硬币或其它硬的东西，这是有时候会发生的，医生也会照张Ｘ光片看看这个东西在孩子身体里已经到了那里。
Every hospital has an X-ray department, and doctors now depend on these photographs for giving them information
 about their patients.
每家医院都有Ｘ光部门，医生们现在就靠这些Ｘ光照片供给他们有关病人的资料。
Dentists also take X-ray photographs of people's teeth to find out if there is anything wrong with the teeth
 which do not show from the outside.
牙医也照病人牙齿的Ｘ光片来查看是否有外表看不到的毛病。
X-rays were first discovered by a German scientist, Wilhelm Konrad Rontgen, in 1895, almost by accident.
Ｘ光最早由一个德国科学家栾琴在一八九五年几乎是无意中发现的。
He and several other scientists were experimenting with passing electric currents through certain gases in a
 special glass tube from which the air had been removed.
他和其他几位科学家在做实验，使电流通过除去了空气的特制玻璃试管中的某些气体。
Then one day Rontgen noticed that, even when the tube was covered with black paper, some strange kind of radiation
 was coming through and making a screen nearby glow.
有一天栾琴注意到即使管子被黑纸所覆盖，也有某种奇怪的辐射穿过并使附近的银幕发光。
Rontgen could not see anything coming out of the tube, but then he discovered that if he put the screen in the
 next room on the other side of a closed door, the rays still seemed to affect it.
栾琴看不出任何东西从管子里出来，但他发现假如他把银幕放在隔壁房间关起来的门的后面，射线似乎还是能对银幕起作用。
The glowing screen showed that the rays could not only pass through black paper but also wood.
这发光的银幕显示射线不但能穿过黑纸，也能穿过木头。
The next thing he found out was that if he put his hand between the rays and a photographic plate, the rays
 would print a shadow of the bony framework of his hand on the plate.
他发现的第二件事情是假如他将手放在射线和感光板之间，射线会在板上印出手骨胳结构的影子。