1910-11. ] Absorption of Light by Inorganic Salts. No. III. 543 
The following table gives the results for the infra-red : — 
Values of A for Nickel Salts in the Infra-Red. 
A. 
<7 = 3 cm. 
d = 1 cm. 
c = -140. 
Fluoride. 
c = -757. 
Chloride. 
c=- 303. 
Bromide. 
c — -488. 
Iodide. 
c = -52. 
Nitrate. 
c = -35. 
Sulphate. 
*684 ju 
1-68 
1-9 
1-97 
1-88 
1-82 
1-96 
•720 
1-74 
1-9 
1-96 
1-82 
1-73 
1-97 
•750 
1-01 
1-46 
1-50 
1-37 
1-26 
1-41 
•794 
•63 
•71 
•78 
•65 
•65 
•70 
•850 
•28 
•33 
•39 
•33 
•32 
•34 
•910 
•37 
•30 
•27 
•285 
•24 
•28 
•980 
•84 
•62 
•59 
•59 
•58 
•61 
1-07 
1-48 
1-46 
1-40 
1-40 
1-28 
1-42 
1-17 
1-67 
2-00 
1-90 
1-89 
1*76 
1-83 
1-27 
1*99 
1-88 
1-75 
1-75 
1-81 
The values of A given in this table and the preceding one are represented 
by fig. 1. To make the curves complete, the values for the ultra-violet are 
added from the fourth article of this series. To facilitate comparison the 
similar set of cobalt curves is printed in this article in fig. 2. 
The effects of increasing the concentration and the temperature were 
also studied. The methods used were the same as for the cobalt salts 
and hence need not be described. The results are given in the following 
tables and represented by the following curves, the heavy line giving the 
increase in A due to concentration and the dotted line the increase due 
to heating. 
Values of A for more Concentrated Solutions. Visible Spectrum. 
A. 
d = 1 
mm. 
A. 
d = 1 mm. 
c = 4‘09. 
Chloride. 
c = 3-19. 
Bromide. 
c = 4*15. 
Nitrate. 
717 ^ 
2*16 
2-03 
681/AfJL 
2-12 
653 
1-68 
1-73 
625 
1-36 
602 
•58 
•84 
582 
•35 
563 
•18 
•38 
547 
•09 
529 
•05 
•43 
514 
•00 
499 
•06 
•44 
486 
•04 
475 
33 
•49 
463 
•35 
453 
•94 
•86 
444 
•73 
434 
2-65 
1-78 
