"A spray can of Ubik," the girl answered, "is a portable negative ionizer, with a self-contained, high-voltage, low-amp unit powered by a peak-gain helium battery of 25kv. The negative ions are given a counter-clockwise spin by a radically biased acceleration chamber, which creates a centripetal tendency to them so that they cohere rather than dissipate. A negative ion field diminishes the velocity of anti-protophasons normally present in the atmosphere; as soon as their velocity falls they cease to be anti-protophasons and, under the principle of parity, no longer can unite with protophasons radiated from persons frozen in cold-pac; that is, those in half-life. The end result is that the proportion of protophasons not canceled by anti-protophasons increases, which means - for a specific time, anyhow - an increment in the net put-forth field of protophasonic activity... which the affected half-lifer experiences as greater vitality plus a lowering of the experience of low cold-pac temperatures.