How it got here: Scottish chemist and physicist Sir James Dewar invented the vacuum flask Iin 1892 as a way to keep liquid nitrogen from warming up and turning into gas in his lab.

A conventional thermos isn't good enough, but a Dewar flask, invented in the 19th century, holds cryogenic fluids like liquid nitrogen at temperatures of -196oc (-321of) for months at a time.

A suitable device was used instead of the original Dewar flask in the phosphorescence attachment of the spectrophotometer.