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^∘{}C. 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 1.21μ. 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.