E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
We generally mean by this expression that degree of Fahrenheits thermometer which indicates the temperature of frozen waterviz. 32° above zero. If we mean any other liquid we add the name, as the freezing-point of milk, sulphuric ether, quicksilver, and so on. In Centigrade and Réaumurs instruments zero marks the freezing-point.