X-射线的发现是一件很有趣味的事情。在一个玻璃管中装上两个电极,接上高电压,然后把管中的空气抽去,空气稀薄到了一定的程度,电子就可以由陰極飞射到陽極上去。这就是所謂陰極射線。陰極射線實際上是一般电子流。在平常的情况下,空气是不导电的,因为空气中的分子阻碍着电子的通行;当空气極为稀薄而兩个电極 The discovery of X-rays is a very interesting thing. Two electrodes are mounted in a glass tube, connected to a high voltage, and the air in the tube is removed. The air is thin enough to allow electrons to be ejected from the cathode to the anode. This is called cathode ray. Cathode ray is actually a general electron flow. In normal circumstances, air is not conductive because the molecules in the air hinder the passage of electrons; when the air is extremely thin and the two electrodes