between the viscosity of liquids and their chbhical nature. 507 
Mean temp. 
>]■ 
Difference. 
Observed (mean). 
Calculated. 
0 
0-38 
-006404 
-006404 
•000000 
9-40 
-005692 
•005706 
+-000014 
18-30 
-005109 
-005126 
+-000017 
27-77 
-004592 
•004604 
+-000012 
35-43 
-004234 
•004239 
+ •000005 
45-29 
-003831 
•003831 
•000000 
53-94 
-003525 
•003522 
-•000003 
62-24 
-003262 
•003260 
-•000002 
72-74 
-002980 
•002969 
-•000011 
80-64 
-002787 
•002776 
-•000011 
90-06 
-002574 
•002570 
-•000004 
98-77 
-002400 
•002400 
•000000 
Acetaldehyde. CHg.COH. 
A considerable quantity of aldehyde, obtained from Kahlbaum, Avas distilled from 
a water-bath, the temperature of which was not allowed to rise above 30°, and the 
fraction distilling' between 20° and 23° was collected separately. This portion was 
then shaken for a few minutes with calcium chloride (comp. Peekin, ‘ Chem. Soc. 
Trans.,’ 1884, p. 475), filtered into a stoppered bottle, and placed in ice for about 
four hours to promote the separation of any metaldehyde. The liquid was again 
distilled, and the portion boiling between 20°'45 and 21°’93 Avas collected. Bar. 
755’6 millims. Corrected and reduced b.p. = 21°'4. 
A determination of the vapour density of this fraction gave 22'49 ; calculated 22'00. 
The observations for viscosity gave :— 
Left limb. 
Right limb. 
Temp. 
Press. 
Corr. 
Temp. 
Press. 
Corr. 
0 
0-32 
100-78 
•000081 
•002666 
0 
0-.35 
100-76 
•000081 
•002659 
5-34 
100-65 
•000084 
•002540 
5-36 
100-60 
•000084 
•002536 
9-55 
100-54 
•000086 
•002440 
' 9-57 
100-49 
•000087 
•002443 
13-91 
100'47 
•000089 
•002346 
13-93 
100-41 
-000089 
•002343 
19 20 
100-31 
•000092 
•002232 
19-14 
100-23 
•000092 
•002237 
In reducing the observations, we have employed the value d (0°/0°) = 0'80092 for 
the relative density, and the expression 
V = 1 + -0315464^ -f - 0569745 ^^ 
for the thermal expansion (Kopp, ‘ Jahresbericht,’ 1847-48, p. 66). 
3 T 2 
