DEFINITION
The Kjeldahl flask is a small pear-shaped flask with a long neck that is primarily used in the Kjeldahl method[1].
INVENTION
The Danish chemist Johan Gustav Christoffer Thorsager Kjeldahl invented[2] the flask that bears his name in 1888 in order to facilitate a method (the Kjeldahl method) that he invented in 1883. Here is his original drawing of his flask (on the left) in his 1888 publication:
Here is a photograph[3] of a Kjeldahl flask:
INVENTOR
Here is a portrait[4] of Johan Kjeldahl: