MONOCLINIC DOUBLE SULPHATES CONTAINING AMMONIUM. 
17 
Cleavage.— The common cleavage of the series parallel r {201} is well developed in 
this salt. No trace of the b {010} cleavage found on the nickel ammonium salt was 
discoverable on the cobalt salt. 
Volume. 
Relative Density.— 
-Five determinations by the 
immersion method gave 
the followin 
results:— 
I. Density for 
16°*8/4° 
. . . 1-9000 
For 20°/4° . . . 
1*8994 
II. 
17°l/4° 
. . . 1-9006 
„ 20°/4° . . . 
P9001 
HI. 
16°-2/4° 
. . . P9037 
,, 20°/4° . . . 
1*9030 
IV. 
16°'3/4° 
. . . 1*9016 
„ 20°/4° . . . 
1-9009 
V. 
16°*8/4° 
. . . 1 "9014 
2074° . . . 
1*9008 
Mean . 
1*9008 
The value accepted for 20" jV 
is P901. 
Pekrot ( loc. cit.) records three determinations of the density of this salt, the values 
obtained being 1'895, P892, and 1*862, and gives as his accepted mean P88. 
Molecular Volume. — ^ — 206‘40. Pekrot gives 210. 
d 1 '901 
Molecular Distance Ratios (topic axial ratios ).—- 
X : \]r : « = 61860 : 8*3753 : 41667. 
Redeterminations of Densities of Alkali-Metal-Cobalt Salts. 
Potassium Cobalt Sulphate, 
K 0 C 0 (S0 4 ) 2 .6H 2 0. 
I. 
Density for 15°*3/4° . 
2*2196 
For 20°/4° . . 
. 2*2186 
II. 
15--1/4" . . . 
2*2203 
to 
0 
0 
0 
. 2*2192 
III. 
„ 15°*2/4° . . . 
2*2175 
„ 20°/4° . . 
. 2*2164 
IV. 
„ 15°*7/4° . . . 
2*2211 
to 
0 
0 
0 
. 2*2201 
Y. 
,, 16°*9/4° . . . 
2*2213 
„ 2074 ° . . 
. 2*2206 
Mean . 
. 2*2190 
The value accepted for 20°/4° is 2*219 
Rubidium Cobalt Sulphate, ftb 2 Co (S0 4 ) 2 .6IPO. 
I. 
Density for 13°*6/4° 
. . . 2*5676 
For 20°/4° . . 
. 2*5660 
II. 
15U/4" 
. . . 2*5679 
2074 ” . . 
. 2*5666 
III. 
„ 15 c '*0/4° 
. . . 2*5684 
„ 2074 ° . . 
. 2*5671 
IY. 
„ 15°*2/4° 
. . . 2*5676 
„ 20°/4° . . 
. 2*5664 
Mean . 
. 2*5665 
'he value accepted for 20 °/V 
is 2*567. 
VOL. CCXVI.-—-A. D 
