IJfDIRECT EFFECT OF X-RAYS OX THE JEXSEN-SARCO.MA 



74- 



while the other sarcoma was irradiated with doses from 280 to 2000 r. 

 The time of irradiation amounted to 3 to 28 min and tli(> lube voltage 

 was 165 kV. A 0.5 mm copper foil and a 1 mm aluminium toil wcvc used 

 as radiation filters. In the later experiments the sarcomas were plac^ed 

 as far as possible from each other. One sarcoma was situated on the 

 right side behind the neck, the other on the loft side near the tail. The 



Table 4. — Formation of Nucleic Acid in Irradiated 

 Sarcoma (only Sarcomas Lying far Apart are 



Considered here) 



<^) Irradiation dose of the other sarcoma 



^") Injected 1 1 days after irradiation. 



<^) Injected 6 days after the last irradiation. 



shortest distance between the boundaries of the sarcomas amounted 

 to about 7.5 cm. In one experiment, the right-hand sarcoma was irra- 

 diated and the left-hand one protected. In the next experiment, the order 

 was the reverse. The radiation dose received by the protected sarcoma 

 was quite small, as was shown by the control with the Sieverts measuring 

 device. In experiment 117, for example, in which one sarcoma was 

 protected with an 8.5 mm thick lead sheet, measurement with the aid 

 of a celluloid measuring chamber showed that the lateral total dose 

 received was 6 r for the right-hand and 4 r for the left-hand one, while 

 the surface of the sarcoma was irradiated with a total of 12 r. A measur- 

 ing chamber indicated that the directly irradiated sarcoma received a 

 dose of 980 r in the same time. 



