Part IT. On Aqueous Solutions. 85 
temperature are accurately known. The deviation is admittedly 
small, but it is considerably greater than the error of observation. 
The deviation of the curve IV from a mean hyperbola is smaller 
than that of curve III, and although the points obtained for 
temperatures between 15°C. and 25°C. indicate an irregularity, 
yet on account of the absence of points in the neighbourhood of 
12° C. it is not considered advisable to attach importance to it. 
The nature of the irregularities mentioned above is brought 
out more clearly in fig. 6, where the ordinates represent the rate 
of variation of viscosity with the temperature and the abscissae 
are temperatures in degrees centigrade. In the following table 
columns 2, 3, 4, 5 and 6 give the abscissae of those points of the 
curves I, II, III, IV and V, where the slope has the value given in 
column 1. 
_ S of S of S of S of S of 
oS: curve 1 | curve II | curve Ili | curve IV curve V 
5:00 == — — 3°0 == 
4-00 = — =: GB . SES) 
3°00 — == 12:0 10-2 20:3 
27D — = 16°5 130) Mls) 
2-25 “= = 15-6 13-2 23:0 
2:00 — = UO [Mo Qes PV) Zoey 
| esx0) = 2:5 ed 24-6 29220 
| 1-60 ae 6-75 | 18-4 27-0 32-0 
1:40 — 10:5 20-0 28°7 34-6 
1-20 = 13:0 22°75 BILD 38-4 
1-00 15) 16°5 27-0 TOD) 43°7 
0:83 5:0 20:0 31:0 39°75 50-0 
0-71 15 ee) 35:6 46 0 54:5 
0 625 95 26°5 39-2 49-7 59-25 
0-55 10:5 29-1 43-4 Oo 62-6 
0:50 12°6 Bob) 45:9 56:7 64:4 
0:40 18:3 40-0 ayez: 66:0 105) 
0:30 26°5 49°5 61:2 C20 80:0 
0:20 37°D 69°5 74:5 = es 
0-10 B57) = == — — 
These values were measured a second time, and a good agree- 
ment was found in the two cases. 
No importance is attached to the cutting of the curves Ill’ and 
IV’, since that depends upon the actual shape of the curve IV, 
fig. 5, in the neighbourhood of 15° C. where the number of points 
is not sufficient to enable an accurate value of the gradient to be 
