"The Homeostat," Doctor Sparke explained, "is about the size of a thin pound box of candy, is enclosed in a titanium case, and is powered by a well-shielded store of nuclear material. Built chest-high into the oceanaut's suit, it is crammed with hundreds of miniature parts much too complicated for me to describe. The Homeostat becomes the vital 'organs' of the oceanaut by means of a plastic tube that extends from the top and is inserted into and coupled to an opening made in the throat just below the Adam's apple. An open system through which water constantly flows, the Homeostat provides the oceanaut with food manufactured from plankton, and oxygen and fresh water derived from the sea. At the same time it eliminates CO2 and other wastes as it maintains a steady flow of vitamins, of coco de mono, a South American drug which checks the growth of hair, and also a psychic energizer that enables the oceanaut to function eighteen hours without tiring."
Louis Wolfe, Journey of the Oceanauts (1968)