484 Drs. Russ and Chambers. Action of Radium [Mar. 14, 



the irradiated emulsion was inoculated into each of six rats, 01 c.c. of a 

 control portion of the emulsion being inoculated at the same time into the 

 opposite axillae of the same animals. No tumours developed from the 

 irradiated material, but in each animal a rapidly growing tumour formed 

 from the control emulsion. 



An experimental series was undertaken on similar lines in order to 

 determine the dosage of irradiation necessary to prevent the growth of the 

 sarcoma tissue. Tumour emulsion was exposed to 0275 millieurie per 

 cubic centimetre, samples being withdrawn after 15, 30, and 60 minutes ; 

 04 c.c. of each sample was inoculated into each of six rats, 01 c.c. of 

 the original emulsion being inoculated into an equal number of other rats, 

 making 24 in all ; the average weight of the rats in these four series was 39, 

 34, 42, and 43 grin, respectively. Measurements of the tumours resulting 

 were made by means of callipers at frequent intervals. 



In fig. 2 are recorded the sum of the superficial areas of the growths in 



20 



1 





to 



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/ 



is 



j Controls 





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/ 



/ 



/ 



/ 



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 Jo 



vl 



t5 



° Days 



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Fig. 2. 



the six rats of each series till 27 days subsequent to the inoculations. The 

 tumours in the control animals showed a vigorous growth ; in Series I, 

 i.e. after irradiation for 15 minutes, a phase of apparent inactivity lasting 



