A set comprising a conical flask, or Erlenmeyer flask, and a two-hole rubber stopper, into which an alcohol thermometer and an enclosed glass tube have been inserted. These items were assembled in this way to discover the boiling point of a liquid. First, the base of the flask would be heated and held in place using a tripod with a metal mesh due to its heat. The liquid would then evaporate and rise into the glass tube, and the thermometer would record the temperature at which the liquid had boiled. The conical flask was invented by the chemist Emil Erlenmeyer in 1861 and is known for its conical shape and narrow neck. It is used to mix substances by swirling them and to heat substances to high, but not intense, temperatures. Round-bottom flask distillation is used for intense temperatures. These flasks were a great improvement on classic laboratory beakers as their narrow necks limited the loss of liquid, the risk of spillage during mixing, and the danger resulting from volatile chemical reactions. They could also be sealed using cotton or stoppers. This piece is from a collection of teaching and laboratory supplies from the Andrés Manjón elementary school in Zaragoza.