I think the brine probably froze at 0° F, which ended up correlating to 32° F for regular water. And the body temperature at 100° F ended up correlating to 212° F for water to boil. That’s the way I understand it anyway.
Fahrenheit temperature scale, scale based on 32° for the freezing point of water and 212° for the boiling point of water, the interval between the two being divided into 180 equal parts. The 18th-century physicist Daniel Gabriel Fahrenheit originally took as the zero of his scale the temperature of an equal ice-salt mixture and selected the values of 30° and 90° for the freezing point of water and normal body temperature, respectively; these later were revised to 32° and 96°, but the final scale required an adjustment to 98.6° for the latter value.
Far fewer people know that 0° and 100° in Fahrenheit also correspond to specific real-world values. 0°F corresponds to a temperature where a brine is made of equal parts ice, water, and ammonium chloride. Such a brine, interestingly, is a frigorific mixture, meaning that it stabilizes to a specific temperature regardless of the temperature that each component started at. Thus, it makes for a really nice laboratory-stable definition of a temperature. Similarly, 100°F was initially set at “blood heat” temperature, or the human body temperature. While not super precise, it was a fairly stable value. As good as anything in the early 1700s.
I think the brine probably froze at 0° F, which ended up correlating to 32° F for regular water. And the body temperature at 100° F ended up correlating to 212° F for water to boil. That’s the way I understand it anyway.
What the hell was the brine that it required it to be 32° below the freezing point of water? Even salt water would have frozen by that point.
Source from a quick Google search: https://gregable.com/2014/06/temperature-scales.html