Absorption Bands of Ammonia GAS in the Visible

Abstract

The article describes an investigation of the absorption spectrum of ammonia gas in the visible region. At 5490A an absorption region was found which was too weak for a complete investigation with the means at hand. On a second band at 6474A measurements on 57 lines are given, and the structure of the band is discussed. These two bands are the fifth and fourth overtones of an ammonia band at 3μ. Some interesting alternations of intensity are pointed out, and comparison is made with other ammonia bands of the same harmonic series. Some features of other portions of the ammonia spectrum are discussed in connection with the bands here investigated.