ray

A radiating line, especially a line of light, actinic r's. Solar r's that produce chemical transformations. Becquerel's r's. R's of light given out by uranium salts after exposure to the sun. They may cause inflammation when applied to the body, bipolar r's. R's leading from one center of radiation to another, as in the amphiaster of an ovum. cathode r's. R's resembling Rontgen's rays, sent out as particles from the cathode in discharges through the vacuum. They consist of five electrons negatively charged, chemical r's. See actinic r's. medullary r's. See medullary radii, under radius, polar r's. See unipolar filaments, under filament. r. fungus. See Actinomyces. Rontgen r's, x-r's. See under Rontgen. [Lat., radius, spoke.]