ON THE THICKNESS AND SURFACE TENSION OF LIQUID FILMS. 
Table IV. 
649 
I. 
ii. 
III. 
IV. 
First order— 
Black. 
b 
, , 
12 
Grey. 
G (1, 5) 
(?) 
(?) 
White. 
W (1, 5) 
131 
147 
Yellow .... 
Y (1, 5) 
178 
200 
Orange .... 
0 (1, 5) 
200 
225 
Red. 
R (1, 5) 
284 
320 
Second order— 
Violet. 
V (2, 5) 
305 
343 
Blue. 
B (2, 5) 
353 
397 
Green. 
G (2, 5) 
409 
460 
Yellow .... 
Y (2, 5) 
454 
511 
Orange .... 
0 (2, 5) 
491 
552 
Red. 
R (2, 5) 
522 
587 
Third order— 
Purple .... 
P (3, 5) 
559 
629 
Blue. 
B (3, 5) 
603 
678 
Green. 
G (3, 5) 
656 
738 
Yellow .... 
Y (3, 5) 
710 
799 
Red. 
R (3, 5) 
765 
861 
Bluish-red . 
BR (3, 5) 
815 
917 
Fourth order— 
Green. 
Ci (4, 5) 
893 
1005 
Yellow-green . 
YG (4, 5) 
964 
1085 
Red. 
R (4, 5) 
1052 
1184 
Fifth order—- 
Green. 
G (5, 5) 
1188 
1337 
Red. 
R (5, 5) 
1335 
1502 
Sixth order— 
Green. 
G (0, 5) 
1479 
1664 
Red. 
R (6, 5) 
1627 
1830 
Seventh order— 
Green. 
G (7, 5) 
1787 
2010 
Bed. 
R (7, 5) 
1936 
2178 
In describing the experiments it is convenient to have a symbol which enables us 
to express the colour shortly. The two films are. distinguished as the right and left 
respectively, and C, and C/ are used to indicate their colours. 
Thus, if the film was uniform in tint, C r =G (2, 5) means—the colour of the right 
film was the middle of the green of the second order. 
If two colours are indicated between brackets they are those of the top and bottom 
of the film respectively. Thus 
C/={B(2, 5), G (3, 5)} 
may he read—the colour of the left film varied between the middle of the blue of the 
second order at the top and the middle of the green of the third order at the bottom. 
If the film displayed any black, the length in millimetres is written first; thus 
C,= {56, W (1, 5), O (1, 0)} 
4 O 
MDCCCLXXXVI. 
