The Infrared Spectrum ofH2Cl

Abstract
The fundamental absorption band due to HCl molecules involving the heavier isotope of hydrogen has been observed, using a cell 700 cm long with gas at atmospheric pressure. It lies in the region of 4.8μ. Both ordinary HCl and samples enriched in H2 were examined. Nineteen lines have been measured in the band of H2 Cl35, and seventeen in the band of H2 Cl37. The estimated abundance of H2 relative to H1 is 1 to 35,000.