Alcohol in Early Thermometers
**Yes: seventeenth-century thermometers could be filled with wine spirit—a distilled alcoholic liquid described in sources as *acquarzente* or “spirit of wine.”** The Accademia del Cimento in Florence developed graduated alcohol thermometers in the mid-seventeenth century; in 1667 its members explained that spirit was more temperature-sensitive and stayed clearer than water.
The word “cognac” needs care. Reliable museum sources identify wine spirit/alcohol, not necessarily Cognac as the modern named beverage. The claim is broadly true if “cognac” is being used loosely for distilled wine spirit, but it is not an exact label for the liquid in every thermometer.