The Effects of Radio-active Ores and Residues on Plant Life. 19 



EXPERIMENTS WITH RAPE SEED 

 to ascertain the effect on germination. 



These tests were made in ten large boxes, each three feet square by six 

 inches deep, filled with unsterilised soil. Only one kind of radio-active material 

 (Ore B) was used (a) incorporated with the soil, (b) enclosed in an earthenware 

 cylinder and inserted in centre of box, (c) enclosed in a glass bottle and inserted 

 in centre of box. These three methods were repeated in boxes to which 

 Complete Fertiliser was also added. The Controls consisted of plain soil 

 (two boxes) and soil dressed with Complete Fertiliser (two boxes). 



(It is probable that the A, B, and G rays are all capable of penetrating 



earthenware. But in the case of the glass bottles, Dr. Dufneld is of the 



opinion that the A and B rays are entirely imprisoned, and only the G rays 



have power to act.) 



NOTES ON THE TESTS. 



The seeds were sown on August 20. Four days later every box showed 

 the soil to be cracking and the germs breaking through. 



On August 26 the box containing radio-active Ore mixed with soil possessed 

 the strongest plants. Next in order came the trials with the Ore placed 

 respectively in a cylinder and in a bottle, within a small radius of which the 

 strong growth immediately arrested attention. Very little difference could 

 be seen between the plain soil Controls, the Complete Fertiliser Controls, 

 and the three boxes treated with Ore and Complete Fertiliser. 



As the three tests with radio-active Ore alone were more forward in 

 growth than those in which the Ore and Complete Fertiliser were used together, 

 it is probable that the Ore and Fertiliser neutralised each other. A note on 

 this point also appears under the Trials with Tomatoes, page 9. 



August 27. The lead was held by the box containing the Ore mixed with 

 soil. Plain Soil Controls appeared stronger than the three boxes treated with 

 Ore and Complete Fertiliser. 



September i. The test with Ore mixed with soil was still the best. But 

 growth was practically as strong around the cylinder and the bottle in the 

 boxes not dressed with Complete Fertiliser, although these two boxes were 

 not uniformly good. Between the remainder there was little difference. 



September 15. By this date the Complete Fertiliser Controls were 

 strongest, next to which came the tests with Ore mixed with soil, both with 

 and without Complete Fertiliser. 



In every instance where Complete Fertiliser had been used the plants 

 exhibited darker foliage. 



Experiments with Rape seed. 



