BETWEEN THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 523 
In reducing the observations, Perkin’s vaiue cZ (4°/4°) = 0'8817 for the relative 
density (‘ Chem. Soc. Trans loc. cit.), and Louguintne’s values (‘Ann. de Chim. et 
de Phys.,’ 4, 11 , 468) for the thermal expansion were adopted. 
’Faking 
= -007655 773 = -002554 (calculated) = -004422, 
= 0°*26 ^3 = 107°-08 ^3 (from curve) — 44°-88, 
we obtain the formula 
18-954 
“ (112-99 + Qi-6522 ’ 
which gives results in good agreement with the observed values ;— 
Mean temp. 
'}■ 
Difference. 
Observed (mean). 
Calculated. 
0 
0-26 
-007655 
•007655 
•000000 
9-88 
-006683 
•006691 
-h -000008 
19-47 
-005900 
•005909 
-h -000009 
.30-25 
•005184 
•005193 
+ -000009 
39-86 
•004667 
•004664 
- -000003 
49-43 
•004219 
•004219 
•000000 
60-18 
•003799 
•003795 
— -000004 
69-13 
•003503 
•003492 
- -000011 
80-59 
•003164 
•003157 
- -000007 
91-74 
•002877 
•002878 
+ -000001 
99-95 
•002695 
•002697 
+ -000002 
107-08 
•002554 
•002554 
•000000 
Ethyl Benzene. CgH^.C^Hj. 
A quantity of this hydrocarbon, obtained from Kalhbaum, was placed over 
sodium for a couple of days and then submitted to careful fractionation. The 
portion boiling between 135°-25 and 136°-25 was re-distilled, and the fraction boiling 
between 135°-85 and 136°-09 was collected separately and digested with sodium 
wire for four days and again distilled. The greater portion boiled between 136°-15 
and 136°-27. Bar. 766*3 millims. Corrected and reduced, b.p. = 135°-9. 
Determination of its vapour density : 
Found, 52-93. Calculated, 53*00. 
The observations for viscosity gave :— 
3 X 2 
