Perishment, Extreme Dilution (Istihlak)

This chapter supplements the preceding one on istihalah. Istihlak (perishment, or extreme dilution) happens when a forbidden food or drink is diluted to such an extent that it is no longer forbidden. For instance, when a drop of blood, or of poison, is diluted in a very larger quantity of water, this will not pollute the water or make it forbidden for consumption. Whereas istihalah is concerned with internal chemical changes in haram substances such that no trace of the latter remains, istihlak is primarily concerned with the mixing of quantities such that it reduces the smaller quantity into total insignificance.