AbstractsPhysics

Typewritten ms. A double modulation system was used to detect molecular absorption lines in the 1.25 cm region. A pip, with a repetition rate of 55 kc, was used for the r.f. modulation in place of a sine wave, resulting in increased sensitivity. Thirty-four lines of methyl alcohol, twenty-five of which had not been reported previously, were measured. These were found to be equally spaced and were grouped into three series. Twenty-nine lines due to a mixture of methyl alcohol and water were measured. These were also equally spaced and were grouped into two series. The arguments in favour of attributing the spectra to pairs of molecules, joined by "hydrogen bonding", were advanced.