APPENDIX A

317

and XII, without any preliminary measurements. Table X
will then be used as already indicated.

TABLE XI.—APPHOXIMATE FLUIDITIES FOR CONVENIENT REFERENCE

Substance
Fluidity

Castor oil at 20° ......
0 1

Lard oil at 20° . ............
1

Sugar solution at 20°, 60 per cent by weight ........
1 77

Water at 20° 2 ............................
100 0

Aliphatic hydrocarbons and ethers at boiling temperature . . ............................
500.

Carbon dioxide at the critical state ...............
5,000

TABLE XII.—RADII LIMITS FOR DIFFERENT FLUIDITY MAXIMA AND l/r

RATIOS *

Fluidity maximum
I r
Radius limits in centimeters

5,000.0
600
0.005 to 0.008

500.0
500
0.010 to 0.015

50.0
400
0.020 to 0.026

5.0
300
0.040 to 0.045

0.5
200
0.074 to 0.081

Calibrating an instrument whose maximum fluidity is below
100 offers difficulties since water at 20° is excluded. The best
suggestions at present are: a 40 per cent solution by weight of
ethyl alcohol in water at 0°, fluidity, 14.0; a 60 per cent sucrose
solution by weight at 20°, fluidity 1.77; freshly distilled aniline at
0.5°, fluidity, 9.95.
The glass-blower should make the bulb C (and K) to have the
shape of two hollow cones placed base to base, in order to secure
good drainage. Bad drainage may be detected by inequality in
the fluidity as determined by the right and left limbs with viscous
liquids at the higher rates of flow. For very viscous liquids the
time of flow must be increased so that drainage difficulties may
be obviated. Increasing the size of the bulbs is no advantage.
The bulbs must be of such size that the left meniscus will not