COBALT CHLORIDE AND CALCIUM CHLORIDE. 



197 



o 



Intensity 

 o 



o 



If 

 Cn 



o 



-.7Z6/" 



-.675 A 



spectrum across the field of view, it was barely possible to see two extremely 

 faint bands which were quite narrow, and which were situated at the shorter 

 wave-length side of the band at 0.662^. They were too faint, however, to 

 set upon with the cross-hair. The next solution in order of concentration 

 2.274 began to transmit faintly at0.770 /4 . The bands at 0.697^ and 0.661 /i 

 were more intense than before. A faint band appeared at 0.624;< and a 

 very faint one at 0.609/*. An extremely faint narrow band between the 

 two just mentioned could be 

 seen with great difficulty. 



A general idea of the appear- 

 ance of the successive regions of 

 transmission and absorption for 

 the solution of concentration 

 2.849 is given in fig. 71. The 

 abscissas denote wave-lengths 

 and the ordinates show esti- 

 mated intensities of transmis- 

 sion. The centers of the red 

 regions of greatest transparency 

 were, respectively, 0.726/t and 

 0.675/j. One absorption band 

 was at 0.697/t and the center of 

 the next band was at 0.661/. 

 The entire region from 0.767/< to 

 beyond 0.660. had the appear- 

 ance of a weak flat band with 

 two maxima of absorption, the 

 one at 0.697^ and the other at 

 0.661/< superposed upon it. The 

 absorption at 0.697^ was more 

 intense than at 0.66 1/t. Beyond FIG. 71. 



0.661/ the general transmission 



was uniformly strong, but not as intense as when the cell contained water 

 alone. The narrow band at 6405 was very faint. The next narrow band 

 had the position given by 6245. This band was slightly more intense than 

 the one at 6095. The wave-length of the latter was 6095. The last two 

 bands had about the same width. The spectrum of the solution whose con- 

 centration in calcium chloride was 2.919, did not differ enough from that 

 of the solution just discussed to merit further comment. For the solution 

 of concentration 3.007 the band at 0.697^ extended from 0.706/i to 0.686^. 

 The bright region lying between the bands between 0.661. and 6405 began 

 at 0.655j; that is, the band 0.66 1// ended rather abruptly at the same wave- 



