=EEV. T. E. EOBINSON ON SPECTEA OF ELECTEIC LIGHT. 
971 
The flash of the discharge is white, with a dense yellow atmosphere, to which I think 
the sodium line No. 8 is due. The Air, E.. spectrum is, with the exception of this line, 
very faint. 
Table XX. — Graphite. 
Air. 
Ntoogen. 
Oxygen. 
Carb. oxide. 
Air. 
Nitrogen. 
Oxygen. 
Carb. oxide. 
C.P. 
C.P. 
C.P. 
C.P. 
E. 
C.P. 
C.P. 
C.P. 
C.P. 
E. 
1. 
32 
33-9 0. 
34. 
O 
33 
45 * 
45-2 1 b. 
45-4 1 b. 
2. 
36-3 n. 
35-8 fo. 
35. 
46-2 / b. 
46-7 J b. 
46-7 n. 
46-7 
3. 
39 
39-8 f. 
37-7 c. 
38-4* 
38-4 fo. 
36. 
49-1 f. 
49-3 f. 
47-9 nc. 
4. 
41-8 
40-3 f. 
37. 
51-6 Ic. 
52-6 n. 
51-31 
* 
51-3 nc. 
5. 
44 
43-3 f. 
42-9 f. 
44-2 fo. 
38. 
53-5 f. 
54-2 J c. 
54-3 n. 
53-6 
nc. 
52 b. 
6. 
45-6vf. 
46-2 f. 
45-5 f. 
39. 
56 * 
55-9 * 
56-3 * 
55-3 
7. 
481 * 
48-5* 
48- 1 f. 
double. 
8. 
50 
50' 1 c. 
51-i c. 
40. 
57-2* 
58-2 fn. 
57 
c. 
57-9 
9. 
52-5 nf. 
52-7 n. 
41. 
33 
58-5 * 
59-1 Tb. 
59-8* 
59-1 j 
10. 
56 
4: 
54-2 X: 
55 '3 * 
56 b. 
56 e. 
42. 
34 
2 1 nc. 
11. 
32 
58-3 nc. 
59-3 c. 
43. 
3-5 I 
3-8 1 nc. 
12. 
33 
1'8 vn. 
2-3 b-m. 
2-6 b. 
2-6 c. 
com- 1 
13. 
5 
♦ 
4-9* 
4 * 
3-6 b. 
pound. ) 
1 
14. 
61 f. 
6-7 c. 
6 nf. 
6 n. 
44. 
5-7 ) nc. 
6-5 
15. 
7-3* 
45. 
e 
9-5 Tn. 
9-1 c. 
16. 
8-7 Tb. 
9 Tb. 
8-3 f. 
8-7 1 f. 
46. 
... L. 
10-7 nTb. 
11-8 Tn. 
10-1 c. 
17. 
10] 
b. 
10-2 b. 
10-4 c. 
10-4 1 f. 
10-7 I f. 
47. 
13 J 
12-4 nb. 
13-4 Tb. 
13-1 
18. 
b. 
11-4 -f. 
11-7 nc. 
48. 
seen. 
14-7 f. 
15 ] f. 
19. 
13 1 
b. 
12 b. 
12 c. 
12-7 1 f. 
49. 
16-7 f. 
16 Tf. 
17 
b. 
17-3 f. 
20. 
14-6 Tf. 
15 ] 
15 n. 
14-7 f. 
50. 
19-6 f. 
18 n. 
19 
b. 
18-6 J f. 
21. 
16-4 I vf. 
1. 
51. 
19-9 Tb. 
20-6 
n. 
22. 
18-5 
18-1 /vf. 
18-4 1 
18 f. 
52. 
22-3 f. 
21-9 n. 
21-9 
b. 
23-2 f. 
23. 
19-9 Tf. 
207 
20 nc. 
21 f. 
53. 
24-3 f . 
— 
24. 
22-8 Tf. 
23-4 b. 
22-7 ne. 
54. 
27 f. 
25-8 
27-2* 
25. 
ft 
24 6* 
25- 1 b. 

24-1 
DO. 
30-3 b. 
29-8 c. 
26. 
26 
•5?- 
26-7 f. 
261 1 * 
25-4 1 * 
56. 
33-5 nc. 
35 c 
27. 
27-1 / 
27-1 j 
57. 
36-5 
36-7 nc. 
35 b. 
36-3 n. 
28. 
302 
29-4 Tf. 
30 8 c. 
58. 

38-9 Tf. 
39 
38-3 n. 
29. 
31 -5 
321 nb. 
doubtful. 
30. 
34 
* 
33-3* 
341 * 
35-8 f. 
59. 
41-9 Tf. 
42-3 n. 
42-3 nc. 
31. 
36-5 f. 
37-5 nb. 
36-31 nb. 
60. 
44-8 nc. 
44-6 n. 
32. 
39 Tf. 
.38-1 f. 
37-5 Jn. 
61 . 
45-6 n. 
45-6 fn. 
33. 
33 
41 ’4 bw. 
38 8 f. 
62. 
63. 
47-5 Tf. 
48-9 b. 
47-5 
42 
41-4 bw. 
41-4 b. 
51-4 Tf. 
The electrodes were two of Mordax’s “ leads,” and must have been nearly pure ; for 
fragments of them burnt before a gas blowpipe without leaving any sensible residue. 
The discharge was wliite except in CO, E. Air, C.P., was taken with Merz, and at an 
early period. 
The next spectra were taken in hopes of obtaining an easy mode of determining the 
lines due to gases. In the first, electrodes of mercm'y send the discharge through the 
vapour of that metal ; its lines therefore belong to Hg exclusively. Then filling the 
same apparatus with any gas, the new lines which appear must belong to it exclusively ; 
or if (as in the case of platinum, Table II.) the electrode be of a metal on which Hg 
does not act, its lines can be insulated ; this, however, assumes that the lines of elec- 
trodes and media are independent. 
6 R 
MDCCCLXir. 
