970 
EEV. T. E. EOBINSON ON SPECTEA OF ELECTEIC LIOHT. 
These spectra are in some respects peculiar, those of tellurium most so. In N, C.P., 
No. 36 is so like the distinctive band of hydrogen that at first I suspected the presence 
of that gas. The only difference I can find between them is that at the negative elec- 
trode it separates into two sharp and bright lines. Still one can scarcely see it, without 
thinking that there is some close connexion between Te and H. 
I have already noticed the extreme brilliancy of its R. spectrum. It is very difficult 
to work with from its rapid dissipation at the negative electrode, which is so great that 
a wire O'Ol in diameter disappears in a few minutes; and the deposit is of extreme 
opacity. In H few lines were seen ; for I was obliged to take them at a distance from 
the electrode, as it became invisible in a few seconds. With arsenic, H, C.P., I was more 
successful ; the centre of the spectrum was a bright cloud, in which only the three bright 
bands and two or three others were visible. But at the negative boundary I got the 
largest number of lines, and the brightest that I ever met in H. The arsenic of course 
soon lined the tube (O' 5 inch diameter) with a dark mirror, through which the flash 
seemed crimson ; but an ellipse opposite the plates which form the slit remained quite 
clear. I suppose the induction of the brass on the tube caused this. 
The potassium (air) is of great beauty ; the double orange * is of as great intensity as 
with sodium. No. 7 is an odd-looking olive band. In H, C.P., only the second orange 
* remains, but it is very bright ; the first one is entirely wanting, but reappears in H, R. 
On exhausting, the second retains its brightness when the rest have vanished. 
Table XIX. — Sodium. 
Air. 
Nitrogen. 
Air. 
Nitrogen. 
C.P. 
E. 
C.P. 
E. 
C.P. 
E. 
C.P. 
E. 
1. 
O 
32 
36-5 vf 
26. 
O 
33 
51-5 nb. 
51-3 c. 
51-6 vf. 
51-3 c. 
2. 
37- 1 f 
double. 
3. 
40-5* 
27. 
52 
4. 
41 "5 n. 
double. 
5. 
49’5 * 
48-1 c. 
28. 
54 f 
6. 
53-4 
29. 
56-5 * 
55-9 c. 
56-6 f 
7. 
55-5 n. 
56-3 » 
55-3 vb. 
30. 
33 
57-5* 
57-2 b. 
8. 
32 
57'5 «• vb. 
31. 
34 
0-5 * 
1-1 f 
59-1 b. 
9. 
33 
2-6 bn. 
32. 
2-9 1 nc. 
10. 
3-5 n. 
3 vf. 
4 * 
3-3 c. 
33. 
4-6 y nf. 
11. 
5-5* 
34. 
5-2 J nc. 
12. 
8 n. 
35. 
8-2 vf. 
7-8 0. 
13. 
10 n. 
10-7 1 c. 
36. 
10-5 c. 
11-3 n. 
14. 
11-5 n. 
11-7 c. 
12-4 j-f 
12-4 nb. 
37. 
12-5 nf 
one here. 
1.5, 
16'5 w. 
17-7 
15-7 f 
38. 
13-5 c. 
13-4 vf 
13-1 nb. 
14-4 c. 
16. 
21-71 Tf. 
many here. 
17. 
24'5 # 
25-4 ]■ f. 
25-4 * 
26-1 c. 
39. 
17-5 f 
18. 
28-1 vf 
40. 
19-5 c. 
19-3 vf 
20-3 c. 
19. 
20. 
30'5 bn. 
33-5* 
30-4 vf. 
33-4 f. 
31-8nb. 
34-1 * 
31-1 f 
35-5 f 
41. 
42. 
28-5 bw. 
26-8 c. 
27-8 c. 
31 nf. 
oU*l bn. 
21. 
38-1 nf. 
37-5 vf. 
38-4 e. 
43, 
33-1 f 
34-7 nf 
22. 
401 vf 
44. 
37-3 f 
— 
23. 
41 '5 w. 
4M nf. 
41-4 f 
41-7 c. 
45. 
39-6 nf 
24. 
33 
45 ‘5 1 nc. 
451 
45-4 1 c. 
45-4 b. 
46. 
45-6 f 
25. 
46'5 J nc. 
47 Jc. 
47. 
52-8 
