Abstract
The absorption spectrum of Eu2(SO4)3–8H2O has been studied over the temperature range 14°K—290°K. Measurements of the absorption lines are given for five temperatures. Intensity variations caused by a change in temperature have been used to establish definitely the existence of levels 21 cm—1 and 41 cm—1 above the basic one, and to indicate the existence of 67 cm—1, 86 cm—1, and possible higher levels. An unusual feature of the spectrum is the constant energy difference occurring between many lines which are most intense at the lowest temperatures.