890 THOMAS ORDWAY AND ARTHUR KNUDSON 



zymes. !N"euberg(a) ascribes the effects of radiation to an inhibitory action 

 of x-rays and radium rays upon the other intracellular enzymes without 

 a corresponding deleterious effect upon the autolytic enzymes. Rich- 

 ards (&) maintains that the radiations affect the activity of the various 

 enzymes or ferments ; that a short radiation may accelerate the activity and 

 a longer be inhibitive so that life processes are subject to marked changes 

 under the influence of radiation. 



Radium emanation according to Bovie (&) affects the nucleus in a man- 

 ner similar to the effect produced by quartz rays. Cell division is inhibited 

 as well as locomotion and ciliary action. He finds no reason to believe, 

 however, that rays are more strongly absorbed in the nucleus than in the 

 cytoplasm nor that the nucleus is more photo unstable than the cytoplasm. 

 The effect upon the nucleus may be due to the more intricate nature of its 

 mechanism' and to its inability to undergo rapid recovery from injury 

 caused by radiation. The radiations affect the protoplasm at the place 

 where they are absorbed and the observed physiological disturbances are 

 responses on the part of the organism to its injured protoplasm. Bovie 

 believes that it is the instability of the physiological mechanism rather 

 than the wave length of the radiation used which determines the nature 

 of the physiological effect produced. The effect of course is different 

 if one wave length penetrates deep and the other only affects the surface, 

 but the difference is apparently due to the penetrating power rather than 

 any specific effect of the wave length per se. 



Kronig and Friedrich agree with Bovie that it is not the quality but 

 the quantity, that is, the total energy absorbed, which produces the bio- 

 logical effect. 



II. Light 



Light has been used as a therapeutic agent for a number of years 

 and its general action is based largely upon hypothesis. From the prin- 

 cipal action outside of the living organism and from the constitution of the 

 latter as well as from its known action upon plants and lower animals a 

 certain amount of speculative theory has been indulged in to explain 

 its action. 



Light is composed of different kinds of rays. These rays are ex- 

 plained as transverse electromagnetic vibrations having their origin in 

 the rapidly oscillating electrons whose periods are the same as the 

 periods of the wave motion. These wave impulses travel with the same 

 velocity in free space (about 186,000 miles per second). The different 

 colors correspond to different wave lengths (or more properly, to differ 

 ent rates of vibration) and vary in length from approximately 3.9 to 7.6 

 ten-thousandths of a millimeter. Waves of a similar character whose 

 lengths fall above or below the limits mentioned are not perceptible to 



