The volume of wool was measured with a gas pycnometer, and its density
was calculated. Samples with a high degree of medullation, low degree
of medullation, and no medullation were measured at five relative hum
idities and over a range of masses. The procedure adopted required a s
ample mass of between 2 and 10 g and used the fourth sequential measur
ement of volume to calculate density at 65% relative humidity and 20 d
egrees C. The total measurement time per sample was 10 minutes. Densit
y decreased as the degree of medullation increased. Non-medullated woo
ls had a density of 1.307 g/cm(3).