DTIM.onKX AXD FISH 



469 



a certain time the fish av(M(^ removed and the decrease of tlie density 

 of the surrounding waier was determined. The fish were then placed 

 in normal water, and the rise in the density of the latter due to the 

 entrance of heavy water molecules leaving the body of the fisch was 

 determined. The results ar(> shown in the accompanying tables. 



Tablk -2. 



Rates of T^oss ok ITkavv Water bv the Fish 



Time in 

 hours 



Initial iieavy 



water content 



of tlie fisli 



Decrease of the 

 heavy water con- 

 tent of the fish 

 after the 

 experiment 



Decrease expected in tlie case of 

 equal distribution of heavy 

 water between fish and surroun- 

 ding normal water 



0.27 p.c. 

 0.27 p.c. 

 0.26 p.c. 



68 p.c. 

 68 p.c. 

 86 p.c. 



.j1 p.c. 

 ()7 p.c. 

 86 p.c. 



It follows from the above that, at least in a small fish, within a few 

 hours all the water molecules leave the body of the fish, making way for 

 water molecules derived from the surrounding water. It should be borne 

 in mind that most fish contain about 80 per cent water. 



