Chemical Constitution of Sahne Solutions. 203 
tinctly visible. Heating did not affect the spectrum. When a saturated solution 
of cobalt chloride in alcohol is allowed to crystallize without the action of heat, it 
deposits red crystals, which are in reality the original hexahydrated salt.* 
Thin wedge-cell, sunlight, Plate XX. 8, fig. 1. 
Cobalt Chloride, CoCl,6H,0.—An aqueous solution was mixed with hydro- 
chloric acid. Plate XX. 8, fig. 2, thin wedge-cell, sunlight. The liquid was 
indistinguishable from the alcoholic solution to the eye, except when examined in 
very thin layers, when it had a greenish colour. 
Measurements taken. 
rN 
At 20°C. . Edge of Absorption Band in the rednear D, . 595 
Absorption Band, : : : ‘ . 562 to 508 
End of visible spectrum, 6 : : : 413 
At 40°C. . Red extremity of the spectrum, . : 724 
The band of transmitted rays measured near C, 699 
Edge of Absorption Band in the red, : : 609 
Absorption Band in the green, 5 : . 562 to 503 
End of visible spectrum, : : : 5 416 
Cobalt Chloride, CoCl,;6H,O dissolved in glycerine.—Purplish solution, thin 
wedge, oxyhydrogen light, Plate XXI. 
r 
At 20°C. . Spectrum begins, . : : : : : 724 
First Absorption Band. . : : ; . 696 to 653 
Second Absorption Band, ; ‘ ; . 627 to 608 
Third and principal Adsorption Band, from 
near D to beyond F, not exactly measurable 
End of spectrum visible, : 6 : : 423 
At 40°C. . Spectrum begins at 6 : : 6 741 
Red rays only barely Adil, 
Absorption Band, . : : : : . 724 to 680 
End of visible spectrum, : . 6 413 
At 100° C. . End of visible spectrum, the ea rays have almost vanished. 
Cobalt Chloride, CoCl,6H,0.—An aqueous saturated solution mixed with 
calcium chloride solution. |The liquid was of the same purple hue as the solution 
in glycerine. Plate XX.c. Thin wedge-cell, oxygen-gas light. 
The measurements were made at the following points, but the absorption bands 
merged into each other. 
r 
At 20°C. . Rays transmitted from . : . : : 718 
First Absorption Band, . A : : . 691 to 659 
Second Dp 55 : : : . 627 to 604 
Third Mis ‘ in the green, . . 560 to 479 
This band is not strong at 20° C. 
End of the visible spectrum, . ‘ : : 400 
* For analysis, see p. 299. 
