Suspension stability was determined according to a
procedure modified from a method described byPriepke,
Wei, Nelson, and Steinberg (1980). This was determined by
measuring the top to bottom ratios of total solids in samples
stored undisturbed in a 20 ml bottle for 5 days at 48C.
Portions (3 ml) were carefully withdrawn with a 5 ml
syringe from the center of the upper 1/3 of the bottle and
from the lower 1/3 of the bottle. Samples from each 3 ml
portion were analyzed for total solids content using a 1058C
drying metho