MONOCLINIC DOUBLE SULPHATES CONTAINING AMMONIUM. 
49 
Volume. 
Relative Density .—Four determinations by the immersion method gave the following 
esults 
I. 
Density for 13°'6/4° 
. 2'0613 
For 2074° . . 
. 2-0600 
II. 
„ 14°'2/4° . . 
. 2-0620 
„ 2074 o . . 
. 2'0608 
III. 
„ 13°-9/4° . . 
. 2-0623 
„ 2074 o . . 
. 2-0610 
IV. 
„ 13°'5/4° . . 
. 2-0631 
„ 2074 “ . . 
. 2-0618 
Accepted value for 20°/4°, 2'061. 
Mean . 
. 2-0609 
Molecular Volume .— = ^"* . 4 - = 216 ‘ 12 . 
d 2-061 
Molecular Distance Ratios {topic axial ratios).— 
x : f : w = 6-2838 : 8-5332 : 4-2078. 
Redeterminations of Densities of Rubidium and Ccesium Cadmium Sulph ates. 
Rubidium Cadmium Sulphate , Rb 2 Cd (S0 4 ) 2 .6H 2 0. 
1. Density for 15°"6/4° . 
. . 2-6963 
For 2074 o . . 
. 2-6951 
II. 
15°-8/4° . . 
. 2-6976 
„ 2074 ° . . 
. . 2-6965 
HI. 
15°'3/4° . . 
. . 2-6984 
„ 2074 o . . 
. . 2-6972 
IV. 
15°-0/4° . . 
, . 2"6942 
„ 2074° . 
. . 2-6928 
v. 
16°-0/4° . . 
. 2-6946 
„ 2074° . . 
. . 2-6935 
Mean . . . 2"6950 
Accepted value for 20°/4°, 2'695. 
Ccesium Cadmium Sulphate , Cs 2 Cd (S0 4 ) 2 . 6H 2 0. 
I. 
Density for 14°"8/4° 
. . 2'95 82 
For 2074° . . 
. 2'9568 
II. 
„ 15°-6/4° . 
. . 2-9572 
„ 2074 o . . 
. 2-9560 
III. 
„ 14°'8/4° . 
. . 2'9567 
„ 2074 ° . . 
2"9553 
IV. 
„ 14°-7/4° . 
. . 2-9593 
„ 2074 o • • 
. 2-9578 
Mean . 
. 2'9565 
Accepted value for 20°/4°, 2'957. 
The former values for the pyknometer method were 2'672 for the rubidium salt, 
and 2'955 for the caesium salt. 
As was fully described in the communication describing the work on rubidium 
cadmium sulphate,* special difficulties were found in carrying out density determina- 
* ‘ Journ. Chem. Soc., Trans.,’ 1896, 69, 445. 
VOL. COXVI.—A. 
H 
