BETWEEN THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 489 
Vapour density: 
Found, 42‘42. Calculated, 42’37. 
The observations for viscosity were as follows :— 
Left limb. 
Riq-bt limb. 
0 
Temp. 
Press. 
Corr. 
Temp. 
Press. 
Corr. 
0 
0-49 
100-42 
•000071 
•005335 
0 
0-44 
100-35 
•000071 
•005324 
5-7G 
100-33 
•000074 
•005017 
5-71 
100-23 
•000074 
•005028 
1015 
100-31 
•000077 
•004793 
10-22 
100-17 
•000077 
004796 
15-45 
100-28 
•000081 
•004548 
15-45 
100-14 
•000081 
•004552 
20-53 
100-25 
•000084 
•004327 
20-54 
100-09 
•000084 
•004333 
25-60 
100-16 
•000087 
•004131 
25-58 
100-02 
-000087 
•004144 
.30-96 
100-01 
•000091 
•003930 
31-00 
99-93 
•000091 
•003936 
37-53 
99-98 
•000095 
•003703 
37-50 
99-84 
•000095 
•003712 
. 
In reducing the observations we have adopted Perkin’s value for the relative 
density d (15715°) = 1'3377, and the expression 
V = 1 + -03130805^ + - 052735^2 - -08133^3, 
already given by one of us (Thorpe, loc. cit.), for the thermal expansion. 
Taking 
7 ^^ = ’005329 7^3 = ’003707 773 (calculated) = ’004445 
C = 0°*46 ^3 = 37°’51 ^3 (from curve) = 17°’82, 
we obtain the formula 
5-8778 
~ (I28’88 A ’ 
which gives values in close agreement with those obtained by observation. 
Mean temp. 
Difference. 
Observed (mean). 
Calculated. 
0 
0-46 
•005329 
•005329 
•000000 ' 
5-73 
•005023 
•005031 
+ -000008 
10-18 
•004794 
•004801 
+ -000007 
15-45 
•004545 
•004551 
+ -000006 
20-53 
•004330 
•004329 
- -000001 
25-59 
•004137 
•004126 
- -000011 
30-98 
•00.3933 
•003928 
- -000005 S 
3751 
•003707 
•003707 
•000000 i 
3 R 
MDCCCXCIV.—A. 
