A filtration technique where suction is applied to the mixture of solid and liquid being filtered so as to pull the liquid through the filter. This technique is much faster than gravity filtration. Vacuum filtration usually involves the use of a vacuum filter flask, a vacuum aspirator, and either a Buchner funnel or a sintered glass crucible. The liquid mixture is poured into the filter (Buchner or sintered glass), the liquid is sucked down into the filter flask by the action of the vacuum aspirator. The solid matter is left on the surface of the filter.