NOVELTY - A physiologically ingestible composition comprises microstructured water consisting of hydrogen and oxygen atoms, and having an ultraviolet spectrophotometric pattern comprising a major absorbancy at 185-250 nm.    USE - The physiologically ingestible composition is used for inhibiting changes in the heart rate of a mammal undergoing stress, e.g. human or a horse (claimed). It is also used for, e.g. increasing the oxygen content of blood and tissues, oxygenation of wounds to increase the rate of healing and to reduce infections; oxygenated organ transplant storage media; tumor oxygenation for radiation therapy and chemotherapy; lung bypass by oxygenated liquids in case of pulmonary deficiencies; carbon monoxide poisoning; mouthwashes; dentifrices; topical, including cosmetic, treatment media (such as skin-care product, make-up product, hair care product, fragrance, body care product, and oral care product); contact lens treating solutions; cell level therapeutic applications; cosmetics and toiletries; food additives; or beverages. Also in in situ or ex situ bioremediation of contaminated (e.g. with petroleum products) surface and ground waters; wastewater, sludge, and animal waste treatment, both by fixed film and by suspended growth methods; rehabilitation of atrophying lakes; biochemical oxygen demand (BOD) measurement techniques; fresh water aquaculture (e.g. fish farming); odor suppression barriers for anaerobic processes; and insolubilization of dissolved contaminants (e.g. Fe and Mn ions) for removal by filtration or sedimentation. Also useful in the fermentation liquor of all kinds of fermentation processes, such as drug production or food processing by microorganisms. Also as solvents for physiological saline isotonic solutions.    ADVANTAGE - The composition adequately oxygenates and structures water insofar that when consumed, whether by internal or external absorption, there is a distinct and definite increase in hydration, oxygenation and healthy metabolic changes regarding organic life processes.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (i) a method for inhibiting changes in the heart rate of a mammal undergoing stress, comprising administering a physiologically ingestible composition as above to the mammal; and    (ii) composition as above comprising dissolved oxygen at 20-150 ppm.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of a system for making and tuning super-oxygenated and structured water.