Plate I, No. 1. 



Diluted solution of Didy- 

 niium chloride in 3599 mm. 

 tube. 



Diluted solution of Didy- 

 mium nitrate in 3599 mm. 

 tube. 



Strong solution of Didy- 

 mium chloride in 5 mm. 

 cell. 



Strong solution of Didy- 

 mium nitrate in 5 mm. 

 cell. 



Plate I, No. 2. 



Diluted solution of 

 Didymium nitrate 

 in 1224 mm. tube. 



Strong solution of 

 Didymium nitrate 

 in 5 mm. cell. 



Diluted solution of 

 Didymium chloride 

 in 1224 mm. tube. 



Strong solution of 

 Didymium chloride 

 in 5 mm. cell. 



