BIOLOGY AND MEDICINE RESEARCH--CONTD,- | . phosphate, it was found that a lipid-like substance, ectractstaf from hog kidney cortex, stimulates the luminescence. This substance was {solated and purified to the extent that one microgram per milliliter will produce a tenfold stimulation of luminescence, investigation. _ Its chemical structure if under Pathology and Physiology--Mice, guinea pigs, and rat posed to cyclotron-prodiced neutrons and to 250-kvp X-rays in or determine their relative biological effectiveness. The paramet studied thus far include tPg0/30 days, cataract induction, and bone-mor¥ow activity, as indicated. by Fe5? uptake in red blood cells and white cell cunts. The preliminary LD, studies are nearly completed and the others arg in progress. The tentative neutron/X-ray ratios for acute lethality are as f$llows: in mice 1 rep neutrons equals about 3.) rep X-rays; in rats 1 rep fleutrons equals“/ 3.0 rep X-rays; and in guinea pigs 1 rep neutrons-~/2.B rep X-rays. Enzyme Chemistry--The investigation of the relation molybdenum and xanthine oxidase, undertaken in collaboration wi group, Was completed. It was not found possible to remove the cate that one atom of molyodenum is combined in a molecule confaining two riboflavin residues. The minimum molecular weight of the xantIine oxidase is in the neighborhood of 200,000, a value which is in agreemegt with the results of ultracentrifuge measurements made in other laboratofies. et DOE ARCHIVES