Cocaine test. Pipette adding cobalt thiocyanate solution (pink) to a sample of cocaine (white) to produce the blue precipitate that is the positive result of this test for cocaine. This standard test is used by forensic analysts and the police to provide evidence against suspected dealers in this illegal drug. The conical flask at upper left contains cobalt thiocyanate solution, which needs to be acidified to ensure detection of some forms of cocaine. Cocaine is an alkaloid drug obtained from the coca plant (Erythroxylon coca). Taken for its stimulating effects, it can be fatal if used in excess. There is also a sample of hashish (a form of cannabis) at lower right (brown).