Negative Liquid Pressure at High Temperatures

IN my paper with Lieut. Entwistle on the effect of temperature on the hissing of water when flowing through a constricted tube (Proc. Royal Soc., A. 91, 1915) I have determined the temperature coefficient of an effect which indicates that the tensile strength of water would, be zero at a temperature between 279°C. and 363°C., with a mean from all the experiments published of 328°C. Sir Joseph Larmor's calculated result, 265°C., quoted by him in his letter in NATURE of June 29, agrees satisfactorily with the experimental value if we take into account the difficulty of getting the precise point at which hissing ceases, and that the result was obtained by extrapolation from observations taken at temperatures between 12°C. and 99°C. Lieut. Entwistle and I have experimented with other liquids-alcohol, benzene, acetone, and ether-and obtained results of a similar character. Experiments are now in abeyance, for my colleague is otherwise engaged.