In an excellent little work recently published on elementary physiology, its author, when treating of the blood and its coagulation, remarks that a low temperature retards its coagulation; and that “blood kept at the freezing-point of water will not coagulate at all.” He adds: “Blood thus kept fluid will, however, coagulate when its temperature is raised; and blood has been thus cooled and warmed till near coagulation for three successive times without losing its coagulability.”

That the lowering the temperature of the blood retards its coagulation is now unquestionable; but the statement that it does not coagulate at all at the freezing-point of water, is new to me.