By the early 1890s, the Pinkerton National Detective Agency employed more agents than there were members of the United States Army.
Iodine monochloride is the chemical compound with the formula ICl. It is a red-brown compound that melts near room temperature. Because of the difference in the electronegativity of iodine and chlorine, ICl is highly polar and behaves as a source of I+. Â»
The iodine reagent used for the starch test is usually prepared by dissolving iodine in water, after potassium iodide has been added to improve iodine's solubility. The resulting compound is a triiodide ion complex that has the ability to produce the intense blue coloration.