318 p. J. LINDOP AND J. EOTBLAT 



acute effects, while in the case of anaesthesia it is the other way round. It may well be 

 that the anaesthetic acts on different organs. I am afraid I cannot tell you anything 

 about the levels of oxygen tension in the animal under anaesthetic because the changes 

 are probably too small. We did try to measure them usmg a polarographic method by 

 sticldng electrodes in different tissues. We did find that when animals are made to breathe 

 nitrogen there is a very rapid drop in the oxygen tension in various tissues, but with 

 an anaesthetic the drop is slow and small. 



