MONOCLINIC DOUBLE SULPHATES CONTAINING AMMONIUM. 
5 
Comparison of the Interfacial Angles (continued). 
Angle. 
KNi sulphate. 
RbNi sulphate. 
CsNi sulphate. 
AmNi sulphate. 
* 
[ao = (100) : (111) 
o / 
48 59 
o t 
48 16 
o / 
47 32 
o / 
47 46 
on =(111):(Oil) 
27 33 
27 19 
27 8 
26 59 
I an =(100):(Oil) 
76 32 
75 35 
74 40 
74 45 
no = (Oil): (111) 
34 46 
35 5 
35 31 
35 8 
[ o a = (111) : (100) 
68 42 
69 20 
69 49 
70 7 
f co =(001): (111) 
34 46 
34 25 
34 0 
33 58 
op =(111): (110) 
43 4 
42 32 
42 5 
42 15 
\cp = (001): (110) 
77 50 
76 57 
76 5 
76 13 
po' = (110): (111) 
57 26 
57 57 
58 31 
58 39 
[o'c = (111): (001) 
44 44 
45 6 
45 24 
45 8 
J 
I bo =(010): (111) 
70 12 
70 25 
70 48 
70 40 
1 
Los =(111): (101) 
19 48 
19 35 
19 12 
19 20 
J 
f bo' = (010): (Ill) 
65 17 
65 11 
65 15 
65 8 
i 
[ o' s' = (Ill): (101) 
24 43 
24 49 
24 45 
24 52 
'sq =(101): (011) 
38 13 
37 56 
37 35 
37 32 
qp =(011):(110) 
86 22 
87 17 
88 23 
88 4 
_ps =(110):(101) 
55 25 
54 47 
54 2 
54 24 
[sq = (101):(011) 
45 17 
45 32 
45 44 
45 30 
< 
qp = (Oil):(110) 
63 43 
63 0 
62 27 
62 23 
L ps' = (110) : (101) 
71 0 
71 28 
71 49 
72 7 
fro' = (201) : (Ill) 
34 43 
35 6 
35 22 
35 25 
op = (111):(110) 
93 1 
92 38 
92 32 
92 5 
Ipr' = (110) : (201) 
52 16 
52 16 
52 6 
52 30 
The average and maximum changes of angle for the various replacements of one 
alkali base by another are given in the small table which follows. 
Double Sulphates containing Nickel. 
Replacement. 
Average change. 
Maximum change. 
K by Rb. 
27 
/ o / 
63 = 1 3 
K by Cs. 
54 
122 =2 2 
K by NH 4 . 
49 
117 = 1 57 
The average and maximum changes of angle when potassium is replaced by 
ammonium are very nearly the same as occur when potassium is replaced by caesium, 
and are twice as great as when potassium is replaced by rubidium. 
