104 PHYSIOLOGICAL CHEMISTRY. 



exactly known. If we start from the figures for the carbon-dioxide 

 tension found by PFLUGER and his pupils, and when we recall, fur- 

 ther, that NUSSBAUM found in the cut-off air of the lungs which 

 is more likely to be richer than poorer in carbon dioxide than the 

 normal alveolar air of the lungs the same carbon-dioxide tension 

 as in the venous blood of the heart, then these observations easily 

 agree with the view that elimination of the carbon dioxide from 

 the blood in the lungs simply follows the laws of diffusion. 

 According to the experiments of BOHR, in which the blood and 

 the expired air were investigated at the same time, and in which 

 he found the carbon-dioxide tension in the blood significantly 

 lower than the expired air and also lower than the alveolar air, 

 such an assumption as the above is impossible. BOHK also wishes 

 to give by his experiments a proof of the view suggested long ago 

 by LUDWIG'S school, namely, that the lungs play a specific secre- 

 tory role in the elimination of carbon dioxide. The necessity of 

 further investigations for the explanation of the reason for these 

 very deviating results obtained by different investigators is ap- 

 parent. 



As the carbon dioxide is always in part combined chemically, 

 and as this part increases with the amount of alkali in the blood, 

 it is evident that the amount of carbon dioxide and the carbon- 

 dioxide tension must not always be parallel. That this is a fact 

 has been shown by GAULE in experimenting on suffocated dogs. 

 If the amount of alkali in the blood be diminished, then, naturally, 

 the amount of carbon dioxide will be decreased. Such a behavior 

 is found in poisoning by mineral acids. WALTER found only 2-3 

 vols. per cent carbon dioxide in the blood of a rabbit which had 

 had hydrochloric acid introduced into the stomach. In the coma- 

 tose state of diabetes melitus the alkali of the blood seems to be 

 saturated in great part by an acid combination (ft oxy butyric acid) 

 (STADELMANN, MINKOWSKY), and correspondingly MLFKOWSKY 

 found in the blood in comatose diabetes only 3.3 vols. per cent 

 carbon dioxide. 



In regard to the carbon-dioxide tension in the tissue, we must 

 assume a priori that it is higher than in the blood. This is found 

 to be true. STRASSBURG found in the urine of dogs and in the bile 

 a carbon-dioxide tension of 9$ and 7$ of an atmosphere, respect- 



