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



NASTURTIUM continued. 



with Ore or Residue, although the farmyard manure and guano sections 

 still remained the most vigorous in growth. In this connection see note 

 under Lettuce concerning farmyard manure, page 5. 



Some experiments on Tomatoes and other subjects were commenced 

 with Ore and Residue from the same source as that used for the Nasturtiums, 

 but as the material was received very late in the season the trials could not 

 be completed. 



EXPERIMENTS WITH BLACK OXIDE OF 

 URANIUM ON FLOWERING ANNUALS. 



As only a very small quantity of the above material was available, the 

 trials with it were necessarily limited in number. 



Four flowering annuals African Marigold, Calendula officinalis (Pot 

 Marigold), Dimorphotheca, and Mignonette were grown, six pots of each 

 subject being tested in each of the four sections stated below, making a total 

 of ninety-six pots : 



Control Plain soil only. 



Black Oxide of Uranium (i part in 2,000 parts of soil). 



Complete Fertiliser (at 8 ozs. to 40 Ibs. of soil). 



Complete Fertiliser and Oxide of Uranium mixed (same proportions as above). 



In every case where it was used, the action of the Oxide of Uranium 

 appeared to retard flowering, and to affect the foliage and growth much 

 in the same manner as a nitrogenous manure. 



The best results were obtained from the mixture of Uranium and complete 

 fertiliser. 



COPYRIGHT 



" Control " Oxide of Uranium Complete Fertiliser 



plain soil only. and soil. and soil, 



Specimens of the Trials with Flowering Annuals. 



