204 
PROFESSOR W. R. HARTLEY ON 
Cobalt. 
The metal and oxide were both examined. The lines photographed were compared 
with those measured bj Liveiistg and Dewar in the arc and spark. (‘ Phil. Trans.,’ 
vol. 179, p. 231.) 
Measurements were made with the ivory scale, and all the lines were identified. 
The oxide and metal, as in the case of nickel, give the same spectrum. The 
exposure of the oxide was double that given to the metal. As in the preparation of 
malleable cobalt, some maganese is added ; the bands and lines of this element appear 
in the photograph, but less distinctly than in the metallic nickel. 
Liveing and 
Dewar’s 
1 ! 
Scale 
numbers 
1 
A ■ 
X. 
measurements. 
Remarks. 
X. 
91-2 
24277 
4119 
4120 Hdggins. 
99-8 
2.5026 
3996 
.3997-3 
On comparing the two series of 
107-3 
25640 
3899 
3905-2 
wave-lengths it will be seen that 
109-0 
25804 
3875 
3873-2 
the difference between them is 
111-15 
25990 
3847-5 
3844-8 
rather larger than usual, which 
131-0 
276-28 
3819-5 
, , 
appeal’s to be due to the scale 
131-85 
27688 
3612 
.3611-3 
not being quite accurately ad- 
132-6 
27755 
3603 
3601-6 
justed between certain points 
133-25 
27805 
3596 
3594-4 
which are clearly indicated. 
135-1 
279.50 
3578 
3577-4 
The wave-lengths do not approxi- 
(more probablv 
mate so closely to Liveixg and 
3574-9) 
Dewar’s measurements as is the 
135-75 
28000 
3571 
3568-9 
case with those in the nickel 
139-4 
28280 
3536 
3532-8 
spectrum. 
139-9 
28320 
3531 
3529-3 
140-1 
283.35 
.3529 
3528-4 
140-3 
28352 
3527 
.. 
141-4 
28437 
3517 
3517-7 
141-8 
28467 
3513 
3512-0 
142-15 
28495 
3509-5 
/ 3509-3 1 
\ 3509-7 / 
142-7 
28.537 
3504 
" 3502 
143-6 
28607 
3496 
3495-1 
145-7 
28710 
3483 
3482-7 
146-5 
28835 
3468 
3465-2 
147-0 
28878 
3463 
.3462-2 
147-2 
28895 
3461 
3460-6 
147-9 
28953 
.3454 
3452 9 
148’4 
28995 
3449 
r 3448-6 1 
{ .3448-9 / 
149-0 
29045 
3443 
3443-0 
150-2 
29187 
3432 
/ 3432-9 1 
\ .3432-4 / 
152-2 
29285 
3415 
3414-2 
152-4 
29300 
341.3 
/ 3411-7 1 
1 3412-0 / 
152-9 
29336 
3409 
3408-6 
153-3 
29365 
3405 
3404-5 
• 
