SUBJECT INDEX 



Absorption, 143 

 of beta rays, 68 

 cells, tissue, 36 

 formulas for x-rays, 20 

 of gamma rays, 71 

 law of Beer, 145, 149, 151, 152, 155 

 law of Owens, 15 

 theory of bands, 163 

 of ultraviolet light, 133 

 in general, 143, 144 

 selective, 143 

 by ozone, 167 

 of x-rays, by aluminum, 28, 29 

 by concrete, 38 

 by lead, 37 

 by presswood, 48 

 by tissue, 48 

 by tungsten, 31 

 by water, 48 

 Absorption bands, of acid hematin, 154 

 of blood serum, 159 

 of cholesterol, 163 

 of ergosterol, 163 

 of oxyhemoglobin, 154 

 of pepsin, 159 

 of phenylalanine, 159 

 of proteins, 158, 159 

 of tryptophan, 159 

 of tyrosin, 159 

 Absorption coefficients, atomic, 15 

 composite, 28, 29, 30 

 mass, 20, 21 

 Absorption measurements, x-rays, 27 

 Accommodation, of nerve, 225 

 of vision, 108 

 amplitude, 108 

 Helmholtz's theory, 107 

 loss with age, table for, 108 

 Achromatic lens, 322 

 Achromatic objectives, data for, 318 

 Acid hematin absorption, 154 

 Acoustic intensity, 260, 266 

 aural mechanism response to, 267 



Acoustic intensity, in object space, 254 



pressure relations to, 259, 260 



transmission deafness, 277 

 Action potential, 216 



characteristics, 219 



diphasic, 217, 218 



monophasic, 216, 219 

 Activation, 163 



ultraviolet, 162 

 Acuity of vision, 127 

 After potentials in nerves, 221, 222 

 Air-wall ionization chamber, 44 

 Alpha rays, 55, 57, 63, 64 

 Alpha-rhythmic brain potentials, 238, 

 239, 242, 243 



suppression of, 242 

 All-or-none law, 212, 306 

 American Standards Association loud- 

 ness contours, 289, 295 

 Amici prism, 150, 151 

 Anabolism, calcium, 133 

 Angular aperture, 317, 325 

 Antirachitic activity, 161-163 

 Antirachitic response to ultraviolet radia- 

 tions, 161 

 Aperture, working, 327 

 Apochromatic objectives, 319, 322, 324 

 Applicators, radium salt, 70 

 Aqueous humor, 102 

 Ascaris eggs, 86 

 Astigmatism, 112 



Atmosphere, absorption of solar radia- 

 tion by, 133, 134 



blue color of, 133 



spectral transmission of, 133, 134 

 Auditory biophysics, 253 

 Auditory canal, 261 

 Auditory cochlear patterns, 306, 308 

 Auditory mechanism, 253, 260, 267, 302 

 Auditory process, 253 

 Auditory sensations, 253 

 Aural harmonics, 300, 302 

 Aural membrane, 302, 305 



367 



