20 



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



CONCLUDING OBSERVATIONS. 



Those of my readers who have had sufficient patience to closely examine 

 the foregoing pages will probably agree with me that the experiments there 

 described indicate no more hope of the successful employment of Radium as 

 an aid to either Horticulture or Agriculture than did the trials I carried out in 

 1914. 



In the conduct of scientific research, negative results sometimes prove 

 as important as those which can be definitely affirmed ; and while it would 

 have afforded greater interest to have been able to establish contrary results 

 to those recorded, I venture to hope that these experiments may have their 

 value as the first extensive series of controlled trials undertaken in this country. 

 Reporting on these tests The Times of September 25, 1915, states: " If 

 Mr. Sutton's investigations can be accepted as conclusive and they are 

 so regarded by competent botanists and chemists the farmer and gardener 

 need look for no material benefit from Radium. The chief result has been 

 to emphasise the value of farmyard manure and complete artificial fertilisers. 

 The lessons are of great importance to gardeners." 



I am interested to observe that in some experiments of a more or less 

 similar nature, recently conducted by Dr. Cyril Hopkins at the University 

 of Illinois Experimental Station, U.S.A., equally negative results were obtained. 

 The tests were made with Maize and Soya Beans, and the experimenter 

 states that although the dressings varied in degree from O'Oi milligramme of 

 Radium per acre to a hundred times that amount, in no case was a consistent 

 increase in crop obtained. 



'It would therefore appear that the door is still open to the investigator 

 in search of a plant fertiliser which will prove superior to farmyard dung or 

 the many excellent artificial preparations now available. 



