Change in the Infra-Red Absorption Spectrum of Water with Temperature

By the use of two constant deviation spectrometers in series and a Coblentz linear thermopile, the absorption coefficient of water was measured for various temperatures from 0^ to 95^. The bands found showed maximum absorption at the following wave-lengths There is a shift toward shorter wave-lengths as the temperature increases and also a marked increase in magnitude of the maximum absorption for the bands at. 77,. 98 and 1. 21. These changes are qualitatively explained by Roentgen's hypothesis that water is a mixture of at least two kinds of molecules, presumably ({H₂O) }₂ and ({H₂O) }₃, whose relative amounts change with a change of temperature.