The centrifuge used is the air-driven concentration centrifuge of the vacuum
type described by Bauer and Pickds (4). It is provided with sixteen celluloid
tubes 13 ram. in diameter, oriented at 45* to the axis of rotation. The total
fluid capacity is 120 co. A speed of 27,300 R.P.M. was employed as routine in the
present study. The centrifugal force at the different levels of fluid at this speed
varied from a minimum of 41,000 to a maximum of 78,000 times gravity, giving an
approximate average of 60,000 times gravity.