B. RAJEWSKY 



curve is followed with increasing doses by a steep fall in the survival time till 

 instantaneous death of the animals occurs (few seconds). A new symptom of 

 injury appears when doses of approximately 30,000 r to 1 00,000 r are used. 

 Then the irradiated animals suffer from tetanic convulsions. The lower 

 curve of Figure 3B representing the dependence of the appearance of 

 convulsions on the dose is similar to the general curve of injury. 



The injury in the 'dose-independent' range is to a great extent inde- 

 pendent of the intensity of radiation. The range studied was for single doses 

 lasting from 2-5 seconds to 10 hours {i.e. radiation intensities varied by a 

 factor of 14,400). 



Similar effects also appear in the cases of other animals. The dose range 

 for constant survival time differs for different species both in their extent 



Doses X 



125 250 500 WOO 2000 WOO 6000 1S000 3Z000 6WO0 128000 



3-U 36 3-8 

 LoQ doses 



u-8 SO 



, guinea pigs {-\ [-) and rats 



Figure 2. Dose mortality curves of white mice ( 



(• •) after whole body irradiation 



and in the length of the mean survival time. The differences, however, 

 are not big. Figure 2 represents the results of corresponding irradiations of 

 white mice, guinea-pigs, and rats. In the following we will refer for the 

 sake of brevity to a 3-5 day-effect also with rats. 



PHYSIOLOGICAL PROCESSES 



While instantaneous death {i.e. within a few seconds) after application of 

 large doses may probably be regarded as 'molecular' death caused by 

 destruction of the organism's basic substances, the 3-5-day death is un- 

 doubtedly connected with more or less complicated physiological processes 

 in the irradiated body. Therefore this effect (first described by the author 

 in 1943) was of special interest. Further experiments in this direction 

 were interrupted unfortunately by the war. The studies were resumed 

 in 1948 with my co-workers ^ (Heuse, Aurand, Wilhelm, Pauly, Gerber, 

 Parchwitz and Winkler) using an X-ray set (Heuse and Rajewski^) 



83 



