Abstract: Apparatus and method are provided for the substantial separation on a continuous flow basis of immisicible liquids flowing as a common stream, with one of said liquids substantially encapsulating another of said liquids, in a flow conduit. The conduit comprises an inner surface which is selectively "wettable" by one of the liquids to the substantial exclusion of another of the liquids; and the liquid separator apparatus are disposed in the conduit and operate to substantially separate the liquids, or at least a portion of one of the liquids, from the common liquids stream as that stream flows into contact with the separator apparatus in the conduit.Apparatus and method for the introduction of a liquid on a continuous flow basis into a flowing stream of another liquid which is immisicible therewith and is flowing in a flow conduit are also provided.