Plate II, No. 1. 



O CO CO rH GO 



Strong solution of Erbium 

 nitrate in 5 mm. cell. 



Strong solution of Erbium 

 chloride in 5 mm. cell. 



Diluted solution of Erbium 

 nitrate in 3599 mm. tube. 



Diluted solution of Erbium 

 chloride in 3599 mm. tube. 



Plate II, No. 2. 



Strong solution of 

 Erbium nitrate in 

 5 mm. cell. 



Diluted solution of 

 Erbium nitrate in 

 1244 mm. tube. 



Strong solution of 

 Erbium chloride in 

 5 mm. cell. 



Diluted solution of 

 Erbium chloride in 

 1224 mm. tube. 



