Osmotic Relationships in the Hen's Egg

Data have been given to illustrate the difficulty of obtaining consistent freezing point data with a viscous fluid such as the yolk of the hen's egg and a technique has been described for obtaining reproducible and accurate results consistently. Further freezing point data have been given which were obtained with both fertile and unfertile hen's eggs by the use of a freezing point method previously described by the writer. These data show that there is a pronounced difference between the freezing points of the yolk and the white in contrast to data obtained by the use of the same method by Howard who found the freezing points of the yolk and the white to be the same. It was shown by freezing point determinations that even in a mixture of yolk and white osmotic equilibrium is slowly arrived at. This again emphasizes the fact established by Smith and Shepherd that since osmotic equilibrium between yolk and white is slowly arrived at, the postulation of a vital activity at the yolk membrane is unnecessary, since the steady state previously postulated need not be assumed to exist.