<P> There are several exact definitions of a "drop": </P> <Ul> <Li> In medicine, IV drips deliver 10, 15, 20, or 60 drops per mL . Micro-drip sets deliver 60 drops per mL and 10, 15, or 20 drops per mL for a macro-drip set . </Li> <Li> Prior to the adoption of the minim in the early 19th century, the smallest unit of fluid measure in the Apothecaries' systems of the United States customary units and pre-1824 English units was, while inexact, presumed to be equal to 1 / 60 of a fluid dram or 1 / 480 of a fluid ounce . </Li> </Ul> <Li> In medicine, IV drips deliver 10, 15, 20, or 60 drops per mL . Micro-drip sets deliver 60 drops per mL and 10, 15, or 20 drops per mL for a macro-drip set . </Li> <Li> Prior to the adoption of the minim in the early 19th century, the smallest unit of fluid measure in the Apothecaries' systems of the United States customary units and pre-1824 English units was, while inexact, presumed to be equal to 1 / 60 of a fluid dram or 1 / 480 of a fluid ounce . </Li>

What is the volume of a drop of oil