chapter  10
Pages 24

The student of pharmacy will have used filtration extensively in the collection of precipitates in chemical analyses or in the preparation of parenteral fluids and will, therefore, anticipate the definition of filtration as the removal of solids suspended in a liquid or gas by passage through a pervious medium on which the solids are retained. The pervious medium or septum is normally supported on a base, and these, together with a suitable housing providing free access of fluid to and from the septum, comprise the filter.