INDEX 



335 



v — usually an independent variable; distance 

 X — electromagnetic radiation (X rays) 

 X rays, 77, 78-79, 93-96, 243, 252 



absorption of, 94 



characteristic (Moseley; atomic number), 

 77 



discovery of, 234 



effects of, 243, 252 



in medical diagnosis, 94-97 



nonmedical applications of, 235 



penetration by, 68 



properties of, 78-79 



therapy by, 93, 234 ff 



wavelength, 77 

 X-ray diffraction, principle, 127 



method of isomorphous replacement in, 

 132 



X-ray burns, 234 



V — usually a dependent variable 

 y — a constant; initial value of y 

 Y — a thermodynamic fraction, A/*'/A//, or 



A3/A.TC 

 Young-Helmholtz theory of color vision, 89 

 Young's modulus of elasticity, 34 



Z — usually an independent variable; number 



of changes carried by an ion 

 Z-line, in muscle, 290 

 Zero-seeking servomechanisms, 301, 302 



