438 



ADVENTURES IN RADIOISOTOPE RESEARCH 



volume were coUected in small dishes containing traces of heparin, the blood 

 was transferred into part A of the glass vessel, seen in Fig. 1. and the vessel 

 closed with soft paraffin. These operations took only a few seconds. About 

 i/o mgm of dry P^O^ was added to the solution m order to neutraUze any 



traces of ammonia present. The vessel was 

 then cooled in the refrigerator, evacua- 

 ted, and sealed off at B. Tube D was 

 then immersed in hquid air, while the 

 other parts of the vessel remained at 

 room temperature. After the lapse of a 

 few hours, the water content of the blood 

 sample was found to be present in the 

 form of ice in tube C After the ice was 

 molten and the water collected in D, 

 this tube was sealed off. The pure water 

 obtained by this procedure was further 

 purified by distillation in the presence 

 of potassium permanganate and sodium 

 peroxyde, and the density of the purified 

 samples determined, using Linder- 

 STROM— Lang's floating drop method 

 (LiNDERSTROM— Lang, Jacobsen and 

 JOHANSEN, 1938). 



2 cm 



Experiment A 



In this experiment, a rabbit weighing 

 Fig. 1. 2.6 kgm was used. 9.2 cc. of heavy water 



having a density of 1.1049 were injected. 

 The time which elapsed after the injection 

 of the heavy water is recorded in the first column of Table 1, while the next column 

 contains data on the density excess of the blood water over normal water, expres- 

 sed in parts per miUion. (The heavy water injected had a density excess of 104900 

 parts per milhon.) The third column contains data on the dilution of 1 cc. heavy 

 water introduced into the circulation. In the fourth column the percentage of the 

 weight of the rabbit which took part in the dilution process is stated. 



The injection lasted 40 sec; the time recorded in column 1 is calculated from 

 the moment half of the water was injected; the first blood sample was coUected 



