S. P. Sadiler on Fischer's Salt. 189 
the azure tint was replaced by a grayish hue, or a light 
color was the closing hue of a series of shades of color. If the 
responded in unequal coloration, as if the water mirrored the 
sky, under this condition of beaut 
do not exhibit the oloration, commonly seen in Lake Leman 
=f with clear blue skies 
through atmospheric constitution, and bluish greenness of tint 
Is the nearest approach to azure hue, which the sky permits, 
€ negative results of chemical analysis, and the agen 
of the effect of reflected and refracted light of the sky, whic 
18 over the water of Lake Leman, led me to the conclusion that 
the cause of color is found in the peculiar hue of the sky, so 
transmitted to the eye by a colorless water. 
Boston, Mass., December 10th, 1869. 
— 
Arr. XXIV.—Coniributions to Chemistry from the Laboratory of 
the Lawrence Scientific School. No. 1X.—On the Potassio- 
Cobaltic Nitrite known as Fischer’s Salt, and some analogous and 
related compounds ; by SAMUEL P. SapTLer. 
THE composition of the double nitrite of cobalt and 
potash, known by the different names of “ Fischer's Salt” and 
“ Cobalt-yellow,’ has long been an open question. The follow- 
18 peculiaz 
N.6 i he formula and results farther on. 
ely Pg aaet ae a distinction between the salt 
formed in neutral eee a, “We f s, 
Which latter he considers as a normal salt. He gives both 
2€0®, 3N,0,+3(K,ON,0,)+3N,0, and €0,0,3N,0.+ 
K,0N,03)+3H26 
* Pogs. A + iv, 12. Ann. Ch. u. Ph., xevi, 218. 
Sir gees pe -oiy ss Aoge Ch., lxxiii, 598. 
