曾经做过这样一个实验。将宝蓝色的硫酸铜晶体碾碎放入坩埚中。用酒精灯的外焰加热。然后用玻璃棒不停地搅拌,水蒸气便从里面一点点儿地冒了出来。纯蓝的硫酸铜粉末在里面不断地净化。一点点儿地变成纯白,白得很彻底、很光洁,纯粹得不加任何修饰。可是,却很少有人知道,再加热30秒的时间,它就会变成如木发一般的黑。白与黑的界限,只是那么短短的一瞬间。 Have done such an experiment. The blue-blue copper sulfate crystals crushed into the crucible. Use alcohol lamp outside the flame heating. Then with a glass rod stirring constantly, the water vapor from the inside a little bit to run out. Pure blue copper sulfate powder in the continuous purification. A little bit of pure white, white very thorough, very smooth, pure without any modification. However, very few people know, and then heated for 30 seconds, it will become like a black wood hair. The boundaries of white and black, just a short moment.