Presumptive tests: A simple test for a given substance using a reagent that changes color when mixed with the substance under investigation.
{"Image DocumentName": "Presumptive tests:A simple test for a given substance using a reagent that changes color when mixed with the substance under investigation.", "Image ImageDescription": "Presumptive tests are not definitive and further confirmatory tests are always required. They are used extensively in forensic science. In general analytical chemistry, presumptive tests are often called spot tests. The first test is simply the use of a powerful light moved across every surface of a crime scene. That yields possible traces for visual inspection.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}