Tests for the presence of dissolved gold in cyanide waters. Test is sensitive down to 4 parts of gold per million parts of water.  Each packette contains 2 pills.  To test, scrape a small portion of a pill on either a mirror or paper towel.  Place one of two drops of solution on the scaping.  Color change indicates dissolved precious metal.  These pills are temperature sensitive.  They should not be subject to temperatures above comfortable ambiant.  Long term storage should be under refrigeration.