1915-16.1 
The Optical Rotation of Sugars, 
209 
a-c^- G alactose. 
In our previous paper the mutarotations of a-<i-galactose in water at 
12° and in formamide at 18° were described. Professor J. C. Irvine having 
kindly supplied us with some specially pure galactose, recrystallised from 
glacial acetic acid, it was dried to constant weight in the apparatus 
previously described, and measurements were made at 20°, with the 
following results (cf. figs. 3 and 4) : — 
Solvent 
Water. 
Pyridine G. and B. 
Formamide. 
Graph 
x 
o 
+ 
Concentration 
grains in 100 
> 2-2460. 
1-7488. 
c.c. solution. 
Time. 
Time. 
[ a ]red. 
Time. 
[«]d. 
6 min. 
+ 131-57° 
23 min. 
+ 120-98° 
9 min. 
+ 152-96° 
10 „ 
127-78 
30 
?5 
112-34 
12 „ 
151-25 
12 „ 
125-34 
45 
55 
106-17 
17 „ 
150-10 
15 „ 
122-22 
60 
55 
102-47 
22 „ 
148-96 
19 „ 
118-21 
90 
55 
100 00 
27 „ 
147-82 
25 „ 
113-09 
120 
55 
97-50 
34 „ 
145-53 
30 „ 
110-42 
180 
93-88 
41 „ 
144-10 
35 
106-86 
240 
55 
91-31 
52 „ 
140-96 
42 
102‘85 
1 day 
74-04 
1 hr. 
5 „ 
137-81 
48 „ 
99-78 
2 days 
55 53 
1 
55 
15 „ 
136-09 
1 54 „ 
97-28 
3 
55 
46-94 
1 
55 
25 „ 
1 34-38 
1 1 hr. 0 „ 
94-61 
4 
55 
+ 46-94 
1 
55 
35 „ 
132-66 
1 „ 7 „ 
92-61 
Constant 
1 
55 
45 „ 
130-66 
1 „ 15 „ 
90-38 
1 
55 
55 „ 
128-95 
1 »? 25 „ 
88-38 
2 
55 
10 „ 
126-94 
1 „ 35 „ 
86-82 
2 
55 
25 „ 
124-94 
1 „ 45 „ 
85-26 
2 
55 
43 „ 
122-94 
1 „ 58 „ 
83-93 
3 
55 
9 „ 
120-65 
2 „ 15 „ 
82-37 
4 
55 
37 „ 
112-65 
2 „ 30 „ 
81-03 
4 
55 
51 „ 
110-93 
2 „ 45 „ 
80-59 
5 
55 
12 „ 
108-65 
3 „ 2 ,, 
79-70 
5 
55 
35 „ 
107-22 
4 „ 11 „ 
79-25 
6 
55 
2 „ 
105-50 
5 „ 30 „ 
79-25 
6 
55 
22 „ 
103-50 
24 „ 
+ 79-25 
23 
55 
42 „ 
89-20 
24 
55 
20 „ 
88-63 
K = 0-009601 
26 
55 
32 „ 
87-77 
Calc, initial 
Hd = 
29 
55 
30 „ 
87-77 
+ 139-36°. 
48 
55 
+ 87-77 
Extrapolated 
initial 
K 
fal?? = + 139-50°. 
= 0001988. 
Calc. 
initial 
i i 
, a, 
+ 155-25°. 
Extrapolated 
initial 
1 
[- 
g = +155-0°. 
VOL. XXXVI. 
14 
