Temperature. ºC. ηZ found.Z calculated.
500.0283228228.00
450.0305246246.55
420.0352284266.75
380.0368297289.00
340.0410330313.06
300.0419339339.00
260.0445359367.80
220.0492398396.47
200.0511412412.00
180.0531428428.00

EFFECT OF TEMPERATURE UPON VISCOSITY.--GUM VIII.

Temperature. ºC. ηZ found.Z calculated.
500.0430347347
460.0475383371.14
420.0502405397.09
380.0510411424.73
340.0575463454.06
300.0602485485
260.0637513517.82
220.0667538552.25
200.0707570570
180.0755609583.07

The constants for the first gum are those given in the preceding column, while for the latter they were--

A = 771.9: B = -11.15: C = 0.053

As will be observed, the effect of heat appears to be the same upon the two typical gum arabics quoted above, an increase of temperature from 18° C. to 50° C. decreasing the viscosity by nearly one half in both cases, and the same seems to be true of most gum arabics. Roughly also the same holds good for Ghattis, as the following numbers show:

Gum.Z at 18° C.Z at 50° C.
Gum arabic.1016579
Gum arabic.428228
Gum arabic.609347
Gum arabic.581258
Ghatti.572306
Ghatti.782418

The following table shows the effect of heat upon the viscosity of a typical Ghatti:

GHATTI GUM NO. 15.--VISCOSITY.

Temperature.
°C.
ηZ.
500.0517418
460.0581468
420.0628506
380.0726585
340.0788635
300.0857691
260.0889717
220.0919741
200.0946763
180.0964777