A number of spectrograms have been obtained showing the K absorption limit of sulphur. The absorption was due to sulphur in the gypsum (Ca SO4. 2H2O) crystal used in the analysis of the M series absorption spectra of the platinum group.
Proceedings of the Iowa Academy of Science
©1926 Iowa Academy of Science, Inc.
Rogers, R. A.
"Further Evidence of the Effect of Valence and Chemical Combination on the K Limit of Sulphur,"
Proceedings of the Iowa Academy of Science, 33(1), 236-237.
Available at: https://scholarworks.uni.edu/pias/vol33/iss1/53