16 



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



SERIES 2 continued. 

 EXPERIMENTS WITH ONIONS. 



Variety Button's Improved Reading. Sown April 26. 



WEIGHT OF PRODUCE. 



MATERIAL USED. 



Approximate 



COST From open 



of dressing ground plots, 

 2] square yards. each 2 ; 



square yards. 



From open ground plots, each 

 2 , square yards, to which Com- 

 plete Fertiliser to the value of 

 about Id. had been applied. 



Notes during Growth. Signs of vitality were first seen in the Farmyard 

 Manure Control and in the plots dressed with Coal Dust, Nirama, and Ore B, 

 but the most regular germination was found in the tests with Pure Radium 

 Bromide. 



Two months after date of sowing, Farmyard Manure Control was most 

 uniformly strong in top growth, the unmanured First Control and Pure Radium 

 Bromide being weakest. 



A month later, Farmyard Manure Control still held first place, but there 

 had been considerable improvement in the plots dressed with Vanadium Sand, 

 McArthur's Sand, Slime or Mine Residue, Ore B, and Pitchblende Concentrates, 

 in which the plants were now almost equal to the Farmyard Manure Control. 

 The Duplicate Control (unmanured) had also made great progress and was but 

 little inferior to any of the foregoing. This, however, was somewhat curious 

 in view of the fact that in the experiments with Vegetable Marrows, Spinach 

 Beets, and Carrots, the Duplicate Controls had not improved to the sanu- 

 extent. 



