80 



ABSORPTION SPECTRA OF A NUMBER OF SALTS 



showing a single region of transmission, extending to about X6500 in the red. 

 It is interesting to note that by means of the radiomicrometer we are able to 

 study another region of transmission which reaches a maximum near X9000. 

 From this point the absorption rapidly increases until the region of water 

 absorption is reached. It was not possible to determine whether the solu- 

 tion again became transparent beyond this point, on account of the water 

 absorption. 



75 



z 

 o 



50 



25 



0.5^ 



Nickel Chloride 



Cell Depth 3mm 

 Concentration 2 74 N 



'0.7// 



0.8// 



Fig. 36. 



1.18 



Nickel Nitrate. 



Fig. 37, which represents the second column of table 18, gives the trans- 

 mission, as observed, for a solution of nickel nitrate, concentration 1.68 nor- 

 mal and 5 mm. absorbing layer. This figure is almost exactly analogous to 

 the curve for nickel chloride, just discussed in the preceding paragraph, and 

 shows maxima at X5400 and X9000. There is complete absorption in the 

 region X7000 and beyond l.lfx. Figs. 36 and 37 represent approximately 

 equal amounts of the chloride and nitrate respectively, and are very similar. 



75 



o 



50 



25 



Nitrate 



Cell Depth 5 mm 

 Concentration 1.68 N 



0.5// 



0.8// 



Fig. 37. 



1.18 



Nickel Sulphate. 



The curve representing the last column of this table is given in fig. 38. 

 The concentration of nickel sulphate was 1.108 normal, and the depth of 

 absorbing layer was 5 mm. It will be seen that this solution is slightly more 

 dilute than the other two solutions of nickel salts studied; and that in no 



