144 Oxygen Relations in Autolysis 



previously iised.^'^ The oxygen-compounds enumerated below 

 were introduced into the digests as they rested in a Hearson in- 

 cubator. Oxygen was introduced into duplicate jars of the digest 

 as they stood in the incubator, the tube from a commercial cylinder, 

 with reducer, leading through the thermometer-aperture in the top 

 of the incubator, the thermometer having been removed. It was 

 not found possible to estimate the amount of oxygen passed into 

 the digests from the cylinder, but the bubbles were released at about 

 a rate of two per second. The digests were shaken daily, sometimes 

 several times a day. 



It is conceivable that the application of oxygen immediately 

 after its release from a pressure of 150 atmospheres and directed 

 into the digest might have acted so that inhibition resulted, either 

 from oxidation and consequent modification of the Substrate, or by 

 similar effects upon the enzyme. J. J. Thomson (Phil. Mag. 1903) 

 has shown the condensation power of oxygen ions in cases of sudden 

 release of pressure, but the ionization is low. No such inhibition is 

 exhibited by the results in the present case. 



It is conceivable, too, that the Compounds and gas used here did 

 not afford oxygen in a form available for use in the tissue. If the 

 liver contains catalase, which seems to be the case,''^ peroxides, 

 especially HoOo, would be rendered available; and, if the modern 

 theory of oxidation is correct, such oxygen would be as normal a 

 constituent as we could desire. Oxygen is principally molecular^ 

 under the conditions of these experiments. The case may be dif- 

 ferent for the peroxides used, since it is certain from the work of 

 Loew,^ Lepinois^*^ and others that catalysis differs in different tis- 

 sues and organisms, as judged by the guaiacum reaction. 



^ Bradley and Morse: Jour. Biol. Chem., 1915, xxi, p. 209. 



6 Morse : The röle of halogens as accelerators of tissue-enzyme action ; 

 Ibid., 1915, xxii, p. 125. 



"^ Dzierzgowiski : Arch. des. Sc. biol. St. Petersburg, 1909, xiv, p. 147. 



ß Ionization of O. = 10-12 = 1/22 mol. per liter, water being i.i X lO"'''. 



9 Loew : Catalase, a new enzyme of general occurrence ; Report No. 68, U. S. 

 Dept. Agric., Washington, 1901. 



1*^ Lepinois : Sur les f erments solubles decomposant l'eau oxygenee ; Compt. 

 rend. soc. biol., 1899, li, p. 401. 



