PLATE 5. 
Figure. 
Atomic 
percentage 
of tin. 
Per cent, 
by weight 
of tin. 
jNIagni- 
fication. 
^lethod of cooling 
the ingot. 
Method of 
etching. 
Description. 
48 
Sn 18 
29 • 05 
X 45 
S.c.c. 550° 
HCl + FeCls 
Uniform solid. 
49 
Sn 19 
30-4 
X 45 
S.c.c. 550° 
White crystallisation of 5. 
49a 
30-4 
X 45 
S.c.c. 550° 
J5 
50 
Sn 18 
29-05 
X 45 
C. 501° 
n 
)) 
51 
Sn 20 
31-8 
X 18 
C. 726° 
? j 
Decomposing f3 in a white 
tin-rich matrix. 
52 
31-8 
X 45 
Not chilled 
White 8. Traces of C' 
complex. 
53 
Sn 19 
30-4 
X 800 
Patches of C' complex in 
lighter a. 
53a 
Sn 20 
31-8 
X 600 
Patches of C' complex in 
lighter a. 
54 
Sn 21 
33-15 
X 45 
S.c.c. 72.5° 
7 primary and chill primary. 
55 
33-15 
X 45 
C. 650° 
5? 
Uniform y. 
56 
33-15 
X 45 
S.c.c. 590° 
Dark ?/. Light 8. 
57 
?? 
33-15 
X 45 
C. 580° 
Twinned plates of i;. 
58 
Sn 22 
34-45 
x45 
C. 733° 
Primary combs of y. 
59 
n 
34 - 45 
X 18 
C. 690° 
n 
Uniform y and slender dark 
bars of r). 
