The History of the Calorie
The calorie was not an original unit of measure within the metric system. The history of the calorie began in the mid-nineteenth century.
The History of the Calorie
The calorie is a unit of measure most often associated with the measurement of food energy. It comes from a Latin root, calor, which means heat. Although it’s original use was not restricted to the measurement of the potential energy contained in food, this is where it eventually entered into common usage as ‘calorie counting” became part of Western culture. The scientific community most replaced it with the joule which is the measurement used by the International System of Units (SI).
One of the earliest uses of the word calorie was as a unit of measure in a series of lectures given by Nicholas Clement between 1819-1824. These lectures on the use of heat engines introduced the word to the scientific community. It entered the English language in a translation of the French Physics text by Ganot. It was first defined as being the amount of heat required to raise the temperature of one kilogram (kg) of water from 0 to 1 degree centimeter.
When calorie was more general and used in any number of applications, various formulas for calculating it were used. For example, the rate of heat rise depends on the starting temperature to some degree and this needed to be taken into consideration. Several different types of calories were used in measurements before the joule came into use. The use of the word calorie to measure food energy was rather shaky and did not have much pure scientific relevance. It was mostly just an estimate using some international standards.
Despite the fact that the calorie can not be measured in food energy situations with demanding scientific accuracy, it is part of the culture. Just about everyone knows what a calorie is and low cal foods and drinks need no further explanation. The relationship of the calorie to weight loss or weight gain is studied quite closely. Estimates of the calorie consumption of various activities, although they can not be measure with pinpoint accuracy, are popular also.
The calorie has a relatively recent start as a unit of measure, and it quickly changed into something that was more a symbol and a guidepost than an accurate measurement. The history of the calorie is not long, but it has been long enough for it to find its place in language and find a meaning that is understood by all.