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



RADISH continued. 



It will be observed that every box dressed with radio-active Ore gave 

 a greater total weight (roots and foliage) than did the " control " box which 

 contained plain soil only, and that in six instances the produce of the former 

 exceeded that of the "controls" dressed with farmyard manure or fertilisers. 



In this connection it is important to remember that Radium is said to 

 possess a life of several thousand years, and for boxes and pots it may therefore 

 prove possible to employ soil once dressed with radio-active material for an 

 indefinite period. 



The crops do not indicate conclusively whether better results are secured 

 by mixing the Ore with the soil, or by placing it at the bottom of the box, 

 neither can the correct proportion of Ore to be used be determined, but all 

 the dressings, containing as they did approximately 8 milligrammes of Radium 

 Bromide to the ton, may have been too strong. 



EXPERIMENTS WITH LETTUCES. 



Here also the radio-active Ore used was said to contain approximately 

 8 milligrammes of Radium Bromide per ton of Ore. 



As in the Radish trials, the Lettuces were grown in boxes in the open 

 ground. Particulars of the " controls " and the proportions of Ore used 

 are given in the accompanying table. 



Each box contained twenty-three heads of Sutton's Ideal Lettuce. The 

 plants were put into the boxes May 25th and the heads lifted and weighed 

 July I4th, with the following results : 



LETTUCE TRIALS. 



