“…Marrett recommended that the apparatus should be used with halothane according to an algorithm and patient response but, of course, true concentrations would not have been known xiv . A Fluotec mark II (Cyprane Ltd., Keighley) 27,28 was bolted on the front by some anaesthetists xv but the vaporizer in circle function would have been lost. By then, the army had long ceased to use the apparatus.…”