RESPIRATION IN SOUTHERN WHALES 389 



hydroxide. Immediately the absorption of nitrogen was reversed as is shown m the 

 graph. Octyhc alcohol was added at 23 min. after the commencement of the experiment. 

 The nitrogen content of this sample dropped from 2-29 to 1-40 at the end of i hr. and 

 20 min., a figure little above the solubility of nitrogen in other types of mammalian 

 blood. Subsequently it was found that whale blood would never take up nitrogen to its 

 full capacity when there was contamination with octylic alcohol. This effect was not 

 observed in control experiments on the solubility of nitrogen in fresh pig's blood with 

 and without octyHc alcohol, wherein the solubility was i-ii vol. per cent at 36° C. 



It now appears in the face of these nitrogen "capacities" that the samples of whale 

 blood, whose average content was i-ii vol. per cent, instead of being merely not 

 supersaturated by comparison with the normal nitrogen solubility of blood are in fact 

 all "sub-saturated " by comparison with their own capacity for nitrogen. Such a state 

 of affairs is plainly at variance with the known application of Dalton's Law on the 

 solubility of gases. It can only be explained by postulating either a state of negative gas 

 pressure in the lungs of living whales, which is unthinkable, or a mechanism for dis- 

 posing of dissolved nitrogen from the blood. 



DISAPPEARANCE OF NITROGEN FROM BLOOD 

 In the figures relating to the estimation of nitrogen capacity by aeration of the blood 

 followed by gas analysis (Table IV), it was shown that the volume of nitrogen extracted 

 from the blood was variable. The explanation of this is to be found in the peculiar fact 

 that nitrogen which goes into solution in the blood is not completely recoverable by the 

 application of a negative pressure to the blood as in gas analysis. That is to say that at 

 any rate part of the nitrogen which goes into solution in the blood is retained and does 

 not obey normal solubility laws ; the passage of nitrogen into the blood is to some extent 

 irreversible. 



Evidence of this phenomenon was found in one of the early experiments on nitrogen 

 capacity when the accuracy of the method was being tested. Sample 1 1 was aerated 

 and 20 cc. of the blood were immediately enclosed in the lower Umb of the burette, 

 safely bottled between the main stopcock above and mercury below, so that portions of 

 the blood could be raised to the upper half for gas analysis at intervals with the minimum 

 of manipulation. The blood was aerated at mo hours and immediately transferred to 

 the burette. After evacuation of the upper half of the burette and testing for leaks the 

 first sample was ready to be analysed at 



1 1 17 hours when nitrogen content of blood was 2-53 vol. per cent. 



1140 ,, )) >) )> >) ^'35 " 



1210 ,, „ „ „ ,, I'l? " 



The nitrogen content of this sample, whose capacity was not less than 2-53 vol. per cent 

 (and possibly more since there was inevitable delay in manipulation), decreased by 

 1-36 vol. per cent in 53 min. The method employed precludes any escape of nitrogen 

 from the stored blood ; and in the event of nitrogen being evolved the gas would only 



4-2 



