PHYSIOLOGICAL OXIDATION PROCESSES. 873 



idases to heat the views are contradictory. CZYHLARZ and v. FURTH 

 found that the peroxidases from animal tissues were remarkably resistant 

 to high temperatures, while BATELLI and STERN 1 find that animal peroxi- 

 dases are destroyed even at 66 C. 



According to BACH'S theory on the one hand, substances are nec- 

 essary for the oxidation, which take up oxygen with the formation of 

 peroxides (oxygenases) and on the other hand, substances which are 

 able to transport the oxygen from the peroxides to the oxidizable bodies 

 (peroxidases). In certain oxidations, for example in the phenols, the 

 peroxidases can be replaced by certain metallic combinations. 2 The 

 iron, of the blood pigments, acts in this way in the guaiacum reaction 

 (see Chapter XIV). The oil of turpentine here represents the peroxide 

 and can be replaced by hydrogen peroxide. The oxidizable substance, 

 which becomes blue in the reaction, is the guaiaconic acid in the guaiac 

 gum. 3 



Irrespective of whether the division of the oxidation enzymes into 

 oxygenases and peroxidases can be carried out in all cases, there are 

 various oxidation processes, whose occurrence by a combination of oxy- 

 genase (or peroxide) with peroxidase (or metallic salt) can be explained only 

 with difficulty. According to BERTRAND'S* view the action of plant 

 oxidation enzymes is connected with their manganese content. Never- 

 theless BACH 5 has been able to prepare enzymes from plants which were 

 entirely free from iron as well as manganese salts. Starting from BER- 

 TRAND'S view, TRILLAT 6 has prepared solutions of manganese salts, alkali 

 and colloidal substances, which acted like oxidizing enzymes. DONY- 

 HENAULT 7 has prepared artificial " oxidases " from a faintly alkaline 

 solution of gum treated with a solution of manganese salt. According to 

 EULER and BOLIN 8 the salts of certain organic acids have the ability of 

 setting the oxidation power of manganese salts free. Similar observations 

 have been made by WOLFF. Q In the oxidation of auto-oxidizable substances 

 the presence of extremely small amounts of iron salts may be of advantage, 



!Czyhlarz and v. Fiirth, Hofmeister's Beitrage, 10, 358 (1907); Batelli and Stern, 

 Bioch. Zeitschr., 13, 44 (1908). 



2 Ber. d. d. chem. Gesellsch., 43, 366 (1910). 



3 C. E. Carlson, Zeitschr. f. physiol. Chem., 48, 69 (1906). P. Richter, Arch. 

 d. Pharm., 244, 90 (1906). 



Compt. Rend., 124, 1032, 1355 (1897). 



6 Ber. d. d. ehem. Gesellsch., 43, 364 (1910). 

 6 Compt. Rend., 138, 274 (1904). 



7 Bull. acad. roy. de Belgique, 1908, 105. 



8 Zeitschr. f. physiol. Chem., 57, 80 (1908). 



9 Ann. inst. Past., 24 (1910). 



