Freezing

(frez'-ing). The congelation of liquids, especially of water. F. -fluids, liquid preparations, with boric acid, syrupy or gummy in consistence, in which ti ue-specimens are immersed prior to freezing and section-cutting. F. -machine, an apparatus for producing intense cold by the evaporation of condensed gases. F. -microtome, a microtome attached to a contrivance for freezing artificially the ti ue to be sectionized. It is used with very soft ti ues. F. -mixture, a mixture of salts which absorb heat in undergoing solution. F. -point, the temperature at which a liquid freezes.