Is the glass half empty or half full? shown that a speaker's choice of frame can reflect their knowledge of the environment, and that listeners can be sensitive to this information. Is the glass half empty or half full? "Is the glass half empty or half full?" is a common expression, a proverbial phrase, generally used rhetorically to indicate that a particular situation could be a cause for optimism (half full) or pessimism (half empty), or as a general litmus test to simply determine an individual's worldview. The purpose of the question is to demonstrate that the situation may be seen in different ways depending on one's point
Griess test Griess test The Griess test is an analytical chemistry test which detects the presence of nitrite ion in solution. One of its most important uses is the determination of nitrite in drinking water. The test has also been widely used for the detection of trace explosives containing nitro groups. It is usually necessary to release the nitrite ion from the organic explosive before analysis. This is normally done by alkaline hydrolysis. The "Griess diazotization reaction" on which the Griess reagent relies was first described in 1858 by Peter Griess. Nitrite is detected and analyzed by formation of a red pink