45 
1912-13.] The Absorption of Light by Inorganic Salts. 
usual manner behind a solution of copper chloride of 1 mm. thickness and 
concentration c — *50 being unaffected by rays of wave-length beyond *490 /x. 
A. 
A. 
290mm 
o-o 
257 
■078 
250 
•223 
243 
•368 
233 
•481 
In order to obtain measurements, alcohol was added to the solutions of 
chloride and bromide until both reached a concentration given by c = '0010 
and were practically colourless. In working with such dilute solutions 
Values of A for Solutions in Ethyl Alcohol. 
CuS0 4 , 
c = •0012. 
CuCl 2 , 
c = -0010. 
CuBr 2 , 
c — ‘0010. 
CoCl 2 , 
c = -085. 
CoBr 2 , 
c = ’015. 
?2 
6 d 
05 ~ 
NiBr 2 
c = '040. 
A 
A 
A 
A 
A 
A 
A 
A 
A 
A 
A 
A 
A 
A 
MM 
278 
7300 
MM 
290 
10000 
MM 
316 
10000 
MM 
268 
73 
LLfJL 
266 
500 
MM 
272 
110 
MM 
265 
280 
279 
6100 
300 
8300 
325 
8700 
273 
63 
273 
440 
300 
18 
268 
240 
282 
4300 
310 
5400 
337 
6200 
359 
14 
292 
330 
323 
14 
273 
180 
292 
2500 
320 
1800 
345 
3300 
397 
11 
299 
145 
355 
8 
305 
110 
319 
850 
357 
1200 
375 
1300 
420 
7 
302 
62 
364 
10 
311 
48 
375 
0 
366 
970 
397 
1500 
450 
9 
307 
50 
397 
22 
330 
28 
375 
400 
414 
1500 
313 
35 
416 
24 
333 
23 
385 
170 
415 
1300 
318 
13 
437 
17 
335 
17 
418 
0 
417 
1100 
338 
0 
444 
5 
337 
9 
426 
840 
374 
11 
431 
530 
383 
19 
437 
280 
385 
25 
387 
30 
427 
30 
428 
25 
430 
19 
443 
11 
449 
5 
there is a greater probability than usual of the results being affected by 
the small fraction of water inseparable from the alcohol, but this result is 
unavoidable. 
The curves here obtained bear a considerable resemblance to the curves 
