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



and had the opportunity of making enquiries on the spot. The particulars 

 I had heard were confirmed, and I was also told the following story : 



" A year or more ago a local carpenter who had a heap of soil on 

 his premises found it in the way and threw the material over his small 

 allotment garden. This heap had originally come from the ' dumps ' 

 at the French Radium Mine at Terras, near Truro. It so happened 

 that the soil of this allotment was very poor and never produced good 

 crops. But in the summer following this incident a remarkable improve- 

 ment in the crops was noticed, and only on trying to account for it did 

 the carpenter recollect throwing down the soil and the source from which 

 it was obtained." Those are the broad facts of the story as they were 

 told me. 



No controlled experiments had, however, been carried out in this country, 

 so far as I am aware, until my Firm undertook the trials described in the 

 following pages, with the object of gaining definite information upon the 

 subject and in the interests of scientific research. 



Considerable difficulty was experienced in obtaining either radio-active 

 Ores, or Residues after Radium had been extracted* but I was eventually 

 able to secure several hundredweights of each. 



Various vegetables and flowering plants were experimented with, the 

 series comprising some 600 pots and boxes. In most cases the trials were 

 divided into two sections ; the radio-active Ore or Residue being thoroughly 

 incorporated with the soil in half the number, and placed in a layer at the 

 bottom of the pots or boxes in the remainder. 



The radio-active materials used were : 



Radio-active Ore certified to contain approximately 8 milligrammes 



of Radium Bromide per ton of Ore. 

 Radio-active Ore (from a different source to above) certified to 



contain approximately 9 milligrammes of Radium Bromide 



per ton of Ore. 

 Mine Residue after Radium had been extracted, but certified to 



still contain 1.8 milligrammes of Radium Bromide per ton. 

 Black Oxide of Uranium. 



To ensure accuracy in the comparative tests, equal conditions were 

 maintained by sowing, planting and watering each set of trials on identical 

 dates. 



At a demonstration held at Reading on August 6, 1914, the results secured 

 to date were explained, and a preliminary paper was issued for the use of 

 those present. 



In the following pages are given complete particulars both of the experi- 

 ments undertaken and the conclusions arrived at, as a result of the 

 summer's work. All that has been attempted so far is to ascertain : 



(1) Whether radio-activity has a harmful or beneficial effect upon 

 plant life ; 



(2) Whether, if beneficial, strong or weak dressings of radio-active 

 Ore should be employed ; and 



(3) Whether radio-active material can be used with advantage 

 to accelerate germination. 



It is recognised that the whole subject is in its infancy and that only 

 by patient, and possibly prolonged, experiments can scientific data that 

 will prove of value be obtained. 



