The first attempt to measure osmotic pressure of animal fluids through molecular concentration or by means of determining their freezing-points dates back about twenty years, when Dreser1 in 1892 published the results of his investigations on diuresis as dependent on pharmacologic agents. His method, though, was too complicated for practical purposes.
The merit of having established freezing-point determination as a definite clinical method of practical value belongs to A. von Koranyi2 who, five years later, published his fundamental physiologic and clinical investigations on the determination of osmotic pressure of animal fluids by means of lowering their freezing-points. He was the first to show that the freezing-point of normal blood lies at about 0.56 C. below zero, and that blood taken from individuals with healthy kidneys shows a freezing-point varying between 0.55 and 0.58, while, through retention of end-products of metabolism and the thus resulting deterioration of renal function, a rise3