86 
UR. T. E. THORPE AND MR. J. W. RODGER OX THE RELATIOXS 
Dividing by the first term, and correcting for the expansion of glass, the formula 
for the absolute expansion is found to be 
V = i + *0.129999 t + *05199488 + *07105254 
From this is calculated the following table, giving the volumes of ethyl isobutyl 
ether for every 5° between 0° and its boiling-point :— 
T. 
Vol. 
Diif. 
T. 
Yol. 
Diff. 
! 
0 
100000 
45 
106350 
703 ' 
5 
100655 
655 
50 
107130 
783 
10 
101321 
666 
55 
107929 
799 
1.5 
101998 
677 
60 
108745 
816 ; 
20 
102688 
690 
65 
109582 
837 
25 
103391 
703 
70 
110438 
8.56 
30 
104108 
717 
75 
111316 
878 
35 
104839 
731 
80 
112216 
900 
40 
105587 
748 
A determination of the density at 0° gave 0*75445. This value and the above 
expression for the thermal expansion were used in reducing the observations for 
viscosity. 
Taking 
7 ^^ = *004804 = *002147 (caiculated) *003212, 
ti = 0°*36 jg = 77°*48 ifo (from curve) = 35° 00, 
tlie formula 
98-4046 
■“ (152*69 -f 
is obtained, which gives values agreeing satisfactorily with the observed numbers. 
Isopentane. (CHg).CH.CH..CHg. 
In oLir previous communication we gave a series of values of the viscosity 
coefficients of a sample of isopentane lent to us by the late Professor Schoelemmee. 
The Cjuantity of liquid was very small, and tlm boiling-point varied by nearly 3° during 
the distillation. For these reasons, and also from the fact that the sample Avas obtained 
from petroleum. Are thought it advisable to make additional obseiwations on the 
viscosity of this substance, and, if possible, on a })roduct obtained from a different 
source. 
We have been able to examine three different samples of isopentane made 
resnectively from English, Scotch, and Irish fusel oil by direction of the Photometric 
