378 



REPORT — 188-4. 



Cerium. 



Lockyer has observed the following lines in the Arc Spectrum of Cerium between 

 the wave-lengths 4000 and 3900 :— 39987, 39973, 3993-2, 39924, 39917, 39910, 

 3984-0, 39800, 39778, 39743, 3971-5, 39712, 3900-G, 39021, 3959-8, 39550, 3951-6, 

 3941-8, 3941-4, 39392, 39372, 39305, 3930-2, 39239, 39222, 39191, 39175, 39119, 

 3911-6, 3910-4, 39078, 3901-3. 



Chlorine. 



