矾在中国科技史上的应用历史悠久。在长期的实践探索中,我国古代人民利用明矾的化学属性发明了矾书密写法,即用明矾制成的墨水写字,字隐藏不现,以达到保密目的。其原理是明矾入水后充分溶解至饱和,经过电离和水解会生成氢氧化铝,氢氧 Alum in the history of science and technology in China has a long history. In the long-term exploration of practice, the ancient people of our country invented the alumni secret writing method using the chemical properties of alum, that is, the words written in alum made of ink, the word hidden does not exist, in order to achieve the purpose of confidentiality. The principle is alum into water fully dissolved to saturation, after ionization and hydrolysis will generate aluminum hydroxide, hydrogen