Ebullioscope

The first ebullioscope was invented in 1838 by Honoré Brossard-Vidal, and was used for measuring alcoholic content.

The advantage of this method was that the boiling point is relatively insensitive to other components such as sugars.

Older alcoholimeters were based on measuring the density, which is more sensitive to the presence of other solutes.

[1][2] A famous ebullioscope variant was built by Pierre Marie Edouard Malligand, patented in 1876.

[citation needed] A later version was built by the French chemist François-Marie Raoult,[4] but the difficulty of determining the exact temperature was overcome by the invention of the Beckmann thermometer by Ernst Otto Beckmann in 1887.