Watch glass

Watch glasses are so named because they are identical to the glass used for the front of old-fashioned . In reference to this, large watch glasses are occasionally known as clock glasses.

Watch glasses are also sometimes used to cover a glass of , to concentrate the aromas in the glass, and to prevent spills when the whisky is swirled.

When used as an evaporation surface, a watch glass allows closer observation of or , and can be placed on a surface of contrasting colour to improve the visibility overall.

A watch glass is a circular, Selected quality glass, polished ground edges, slightly piece of glass used in chemistry as a surface to evaporate a liquid, to hold solids while being weighed, or as a cover for a . The latter use is generally applied to prevent dust or other particles entering the beaker; the watch glass does not completely seal the beaker, and so gas exchanges still occur.

watch glass in different size.