372 STUDIES IN GENERAL PHYSIOLOGY 



tions which are characteristic of living matter. 1 If. how- 

 ever, oxygen is absent, the chemical changes will be of an 

 entirely different character. Compounds may be formed 

 which are poisonous for the organism. Araki, for example, 

 has shown that when oxygen is lacking considerable amounts 

 of lactic acid and sugar appear in the urine. If the oxygen 

 supply is normal, these compounds may also be formed from 

 glycogen as intermediate products, but they are soon 

 oxidized further. To the immediate consequences of lack 

 of oxygen are therefore added those which are determined 

 through the presence of lactic acid in the body for ex- 

 ample, a diminution in the alkalinity of the blood. The cells 

 of the kidney are also altered, as evidenced by the albumi- 

 nuria which results when oxygen is lacking. 2 



While there exists a comparatively large number of in- 

 vestigations concerning the chemical side of the effects of 

 lack of oxygen (of which we have mentioned only a few), 

 we have very few biological observations on the same sub- 

 ject. Even careful search of the literature discloses little 

 more than the fact that all animal life-phenomena cease 

 sooner or later in the absence of oxygen, that in higher 

 animals the phenomena of dyspnoea precede death, and that, 

 as Ktihne showed 3 the protoplasm becomes vacuolated and 

 opaque and disintegrates. The observations made upon 

 mountain disease may also be mentioned under this head- 

 ing. It did not seem possible to me that these facts ex- 

 hausted all the biological effects of lack of oxygen. The 

 fundamental importance of oxygen for all life-phenomena 

 rendered it probable, a priori, that an accurate investigation 

 would yield a series of qualitative and quantitative changes 

 in life-phenomena. Such an investigation is, of course, 



1 Physiologische Chemie, Vol. I, p. 126. 



2 Zeitschrift filr physiologische Chemie, Vol. XIX. 



3 Untersuchungen iiber das Protoplasma, 1864. 



