CHAPTER VIII 



EFFECTS OF RADIUM RAYS IN THE SOIL ON GER- 

 MINATION AND GROWTH 



It has been ascertained, as previously pointed out, that soil-air is 

 radioactive. Therefore it becomes a matter of considerable interest 

 to ascertain the effect on germination and growth of passing radium 

 rays through soil in which seeds are planted. The object of the fol- 

 lowing experiments is to answer this question. 



Experiment 32 

 March 4, 4 P. M. 



Unsoaked seeds of " Lincoln" oats (Avena) were sown in soil in 

 three concentric circles, at distances of 7 mm., 22 mm., and 45 mm. 



Fig. 24. Experiment 32. Acceleration of Germination and Growth of Oats bj 

 Placing a Sealed Glass Tube of Radium ( 1,500, 000 X) '" the Soil. The Glass Tube in 

 C is Empty. Cf. figures 8, 25, and 26. 



from the center of the pot. The sealed glass tube of RaBrj (1,500, 

 000 x) was inserted in the soil at the center of the pot, with the end 

 containing the radium at a depth of about 15 mm. below the surface. 

 Control culture similarly arranged, but with empty tube. 



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