SUBJECT INDEX 



589 



Radical reactions, 18-20 



Radioactive isotopes, mutations in Pnra- 



tnecium produced by, 312, 314 

 Radium, effect of, on invertebrate eggs, 

 322 

 on protozoa, 292, 297, 303, 310. 322 

 Radon, effect of, on Amoeba, 294 

 on Pseudocentrotus eggs, 298 

 Rats, 530, 532 



Reactivation, by light {see Photoreac- 

 ti vat ion) 

 of viruses, 335, 351-356 

 Reciprocity law, 386 

 Recombination of atoms and radicals, 

 18-19, 22 

 and cage effect, 15 

 Recovery from radiation effects. 292, 

 293,' 297-303, 306-308, 317 

 (See also Modification of radiation 

 effects : Photoreactivation) 

 Reflecting objectives, 226, 228 

 Reflectors to increase ultraviolet in- 

 tensity, 63 

 Reproducibility of photometric data, 



tissues, 240-242 

 Respiration, effect of radiation on, 296, 



322 

 Reversing layer, 97 

 Rhizopus nigricans, 437, 444, 445 



suinus, 433, 434, 437, 442 

 Riboflavin, specific absorption, 208 

 Ribonuclease, 214, 221, 222 

 Ribonucleic acid (RNA), 400 



{See also Pentose nucleic acid) 

 Ribose nucleic acid (see Pentose nucleic 



acid) 

 RNA (see Pentose nucleic acid) 

 Rodents, 553 

 Rotating sectors, 134 



Saccharomyces cerevisiae, 432-435, 437, 

 439, 441, 442, 444, 445, 447, 448 

 ellipsoideus, 443, 446, 448 

 Salamander larvae, photoreactivation, 



482 

 Sarcomas, 533-534 



probable cause, connective tissue, 534 



muscular elements, 534 

 spindle-cell, 534 

 (See also Cancer) 

 Scattering, ultraviolet, in tissues, 221, 



222, 231 

 Sea urchin, 294-296, 298-305, 307 



(See also genus names) 

 Sebaceous gland tumors, 534, 535 

 Secondary' steps, 1, 17-20 

 Seeds, germless, 272 



Selection rule, 2 



Self-(iuenching of fluorescence, 13 

 Self-reproducing elements, 358 

 Semiquinones, photochemical formation 



of, 16 

 Sensitive cross section, 338 

 Sensitive volume, 338 

 Sensitivity to radiation, differences in, 



during division cycle, 289, 299-302 

 inheritance of individual, 291 

 life cycle, 291, 304, 319 

 species, 292, 304, 319, 320 

 Sensitization to heat by radiation, 317- 



318 

 Sensitized fluorescence, 13 

 Sensitized reaction, 9-12, 29, 31, 34-37 

 Sensitizers, photochemical, atomic, 34-35 

 molecidar, 35-37 

 pigments and dyes, 9-12, 37 

 Serum albumen, ultraviolet absorption, 



208, 223 

 "Single-hit" processes, 34 

 Skin, cadaver, 505-506 

 desquamation of, 488, 500 

 Negro, 508, 510 

 template, 491 

 vitiliginous, 508 

 Skin cancer, 530, 533, 535, 551 

 "farmer's skin," 553 

 Indians, 553 

 keratoses, 557 

 Negroes, 553 

 "peasant's skin," 553 

 precancerous changes, 553 

 "seaman's skin," 553 

 in vineyard workers, 530 

 white races, 553 

 Sky brightness, 114 

 Sodimn sulfathiazole, 392 

 Solutions, photochemical reactions in, 



14-15 

 Somatic mutants, 542 

 Spectral quality of sunlight, 488 

 Spectrum, antirachitic, 555 

 action, 555 

 Balmer, 98 



factors influencing, cloudiness, 555- 

 556 

 dust, 555-556 

 ozone, 555 

 smoke, 556 

 infrared, 114-117 

 maximum absorption, 494 

 mercury arc, 495-496 

 provitamin D, 551, 555 

 solar, 97, 98, 102, 103 

 standard erythemal, 499 

 ultraviolet, 97, 98. 103 



