A. C. REDFIELD AND E. M. BRIGHT 



43 



TABLE II — Conchided. 



Aug. 30, 1918. H variable. R = 5.45 cm. 0.01 cm. slit. Strength of 

 emanation = 60 millicuries. Time of radiation = 75 min. 



SO irregular that it is our belief that their inclusion v^ould only serve 

 to obscure the truth. Seven experiments remained w^hich v^e consider 

 satisfactory in every respect and their results are presented in Tables 

 I, II, and III, and Figs. 5 and 6. It may be added that the rejected 

 experiments, as far as can be judged, agree with the data here pre- 

 sented in showing maximum and minimum effects for beams of (3-rays 

 of corresponding velocities. 



Table I contains the results of two experiments made with the 

 procedure in which the magnetic field, H, remained constant while 

 the radius of curvature, R, of the effective beam of /S-rays varied with 

 each lot of eggs. One of these experiments is illustrated graphically 

 in Fig. 5. Table II contains the results of five experiments made 

 with the procedure in which the strength of the magnetic field, H, 

 varied, while the radius of curvature, R, in which the effective beam 

 of iS-rays moved was the same for each lot of eggs. One of these 

 experiments is illustrated graphically in Fig. 6. Examination of the 

 tables will show that the intensity of the radiation in each beam as 

 measured physiologically, indicated in the third column of the table, 

 and the amount of ionization produced by each beam in air, indicated 

 in the fourth column, both increase rapidly up to a maximum at about 

 the same value of HR and then fall off again as HR increases further. 

 In the fifth column of these tables the ratio of the relative amount 

 of ionization and the relative physiologically effective radiation is 



