TORREYA 



LIBRARY 

 NEW YORK 



uotanical 



UAKUBN. 



December, 1908 

 Vol. 8. No. 12. 



RADIOACTIVITY AND LIFE * 



By C. Stuart Gager 

 I. The Supposed Radioactivity of Plants and ok Wood 



Soon after the discoveries of " contact " electricity and "ani- 

 mal " electricity by Volta and Galvani, plant physiologists began 

 to look for electric currents in plants, and to find therein the 

 explanation of " vital " activity. In a similar manner the an- 

 nouncement of the discovery of radioactivity has been followed 

 by numerous supposed observations of a natural or acquired 

 radioactivity of plants and plant tissues. 



Professor A. B. Greene " was among the first to report that 

 microorganisms, especially species of Staphylococcus, after an 

 exposure of from 24—120 hours to radium rays at a distance of 

 0.5 mm., themselves exhibit phenomena of radioactivity. He 

 considers it uncertain as to whether living organisms can acquire 

 this property, but states that those killed by the action of radium 

 rays can do so. In his experiments the radium salt was enclosed 

 in a vulcanite and brass capsule, and the radioactivity acquired 

 by the organisms lasted for three minutes after the termination 

 of the exposure, and enabled them to photograph themselves on a 

 sensitive plate. Their spores were found to be best for this 

 purpose. 



Lambert^ stated in 1904 that ferments that digest albuminous 

 matter emit Blondlot rays, and that the emission of these rays 

 is the cause of the action of the soluble ferments. 



The experimental demonstration of the emission of the so- 



* This article, with the title ^^Bio-radioactivity, Eobes, Radiobes,'''' forms Chapter 

 V of the author's Memoir on '■'•Effects of the Rays of Radium on Plants''^ (Mem. 

 N. Y. Bot. Garden, vol. 4. Dec. 1908), and is reprinted here with the kind per- 

 mission of the Director-in-Chief of the New York Botanical Garden. — Editor. 



[No. II, Vol. 8, of ToRREYA, comprising pages 253-276, was issued November 25, 

 1908.] 



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