|MadSci Network: Chemistry|
Dear Mr. Miller, The basic science behind most invisible ink reactions is related to acid/base chemistry and requires pH indicators. The ink is a colorless liquid with either acidic or basic pH. After the colorless liquid dries on the paper is becomes invisible. However, even though you cannot see the ink the acidic or basic properties remain on the paper. The next step in the process is to introduce a pH indicator to elucidate the ink. The indicator changes color when it comes in contact with either the acid or base. Red cabbage juice is normally used as the indicator in classrom experiments. The folowing website will take you through the entire process and list the volumes required to try the experiment yourself: http://www.miamisci.org/ph/lpexcite3.html I wish you alot of luck on your book. Your "Invisible" Mad Scientist Dave (hey where did he go??)
Try the links in the MadSci Library for more information on Chemistry.