404 



Profs. G. D. Liveing and J. Dewar. 



[June 1(5, 



5226 the less refrangible of this double line. 



5166-8 5 4 



5064 



5072 



4956-5 both lines of pair, the less refrangible strongly. 



4919-7 



3727 M 



3007-5 



2744-7 



4918 



3722 



3006-5 



2743 



4890-5 



3720 



3000 



2741-3 



4890 



3707-5 



2999 



2736-2 



4871 both lines of pair. 



3/ 0o"5 



2994 t 



2722-7 



4414-5 



3647 



2984 



2720 



4404 



3631 



29'82 



2718 



4382-5 



3502 



2974 



2549-5 



4325 



3492 



2971 



2545-5 



4314-5 



3475 



2967-5 



2541 



4307 Gr 



3465-5 



2965-5 



2535-7 



4271 both lines of pair. 



3440 



2957 



2534 



4071 



3402-5 



2953-5 



2529 



4063 



3272* 



2948 U 



2528*6 



4045 



3246* 



2941 



2527-3 



3898 



3099*5 S 2 



2937 



2524-2 



3886 



3082 



2932 



2523 



3859 



3072 



2929 



2518-3 



3856 



3057 



2912 



2511 



3833-5 



3056 



2871 



2502 



3827-5 



3U46-5 s 



2866*3 



2492 



3825 



3041 



2860-8 



2491-6 



3824 



3036-5 



2836-4 



2491 



3820 L 



3030 



2829-8 



2489-3 



3815 



3024-5 



2824-2 



2485-4 



3767 



3022-5 



2767-3 



2484-6 



3763-5 



3020 T 



2755-2 



2481 



3757-5 



3017-5 



2754-3 



2480 



3745-5 



3016-5 



2749 



2474 



3736-5 



3008-5 



2748 



2465 



3734*5 



It is by no means always the strongest lines which are reversed. 

 For instance, in the group of lines between wave-lengths 5428'5 and 

 5396 there are four strong lines 5423*5, 5414*6, 5403, and 5382*4, 

 which are all much expanded and diffuse when iron is introduced into 

 the arc, but have not been seen reversed by us, while three other lines 

 — 5396, 5405, and 5428*5 — are well reversed, but not much expanded. 



* It is possible that these may have been the copper lines which were reversed, 

 and not the iron lines, which are nearly identical in position. 



