656 BIOLOGICAL EFFECTS OF RADIATION 



fat and protein. Petchenko (286) also finds an increase in fat in Amoeba 

 vahlkampjia after prolonged treatment with 5 or 10 mg. RaBr2. The 

 fat was demonstrated in fixed preparations. 



Some authors have attempted to show that the pH of the cell changes 

 following irradiation. Hoffmann (153) found that the ciUate Opalina 

 when stained with neutral red seemed to become more alkaline after 

 treatment with roentgen rays. A similar observation had been made by 

 Tschachotin (364) for sea-urchin eggs, and for frog and bird erythrocytes 

 exposed to ultra-violet radiation. Lisse and Tittsler (240) also found 

 an increase in the pH of bacterial suspensions after exposure to ultra- 

 violet. Liechti (234) measured potentiometrically the subcutaneous pH 

 of rabbits treated with roentgen rays (1.5 to 4.0 H.E.D.). He found 

 a slight decrease in pH, and he also obtained the same result with a 

 human patient given 1 H.E.D. Magath (249) hkewise found a decrease 

 in tissue pH following exposure to roentgen rays. He studied the effect 

 of 4 to 5 H.E.D. on chick embryos and mouse tumors, using both the 

 quinhydrone electrode and colorimetric tests. When the chick embryos 

 were treated in ovo, the skin mesenchyme and muscle showed a decrease 

 in pH, but not the liver or brain. Neither was there any effect on mouse 

 liver or mouse cancer. All in all, the effect of radiation on cellular pH is 

 not well established, so that no certain conclusion can be drawn from the 

 statements in the literature. 



CONCLUSION 



It scarcely seems possible to summarize all the results we have 

 considered in any brief final statement. The following points have been 

 selected because they seem to be reasonably certain and because they 

 fit into an orderly scheme. 



a. All types of radiation have the same general effect. 



6. In spite of the uncertainty of permeability determinations and in 

 spite of the fact that the more modern and the preferable methods of 

 permeability study have been but httle used in investigating the effect 

 of radiation, the preponderance of opinion is rather strongly in favor of 

 the view that radiation causes a substantial increase in permeability. 

 This increase is caused by all types of radiation from visible light to 

 gamma rays. 



c. There is essential agreement among all those who have attempted a 

 study of protoplasmic viscosity of irradiated cells. In both plant and 

 animal cells, ultra-violet radiation, roentgen rays, and radium all cause 

 first a liquefaction of the main mass of the protoplasm and then, with 

 increase in exposure, a coagulation. 



d. The coagulation produced by radiation is frequently evidenced 

 morphologically by the appearance of vacuoles within the cell. Numer- 

 ous authors have described vacuohzation. Table 5 has been prepared 



