GENERAL CHEMISTRY OF LIFE PHENOMENA 15 



peroxides, e.g. benzoylperoxide, phthalylperoxide, and succinylperox- 

 ide, or inorganic ones, like lead peroxide and manganese peroxide, pro- 

 duced the same blue color in the tincture of guaiacum as the tissues 

 of plants, or watery extracts from the same. The production of this 

 blue color is due to oxidation. The same authors showed, moreover, 

 that the same poisons which in plants prevent the action of oxi- 

 dases - - this is the name given to the enzymes of oxidation prevent 

 also the oxidizing action of the above-mentioned organic and inorganic 

 peroxides upon tincture of guaiacum. Kastle and Loevenhart there- 

 fore conclude that the oxidases, or oxidizing enzymes, in the tissues of 

 animals and plants, are organic peroxides. 



Here we meet with a difficulty, however. Oxidations occur inces- 

 santly on a large scale in the living body, especially at the temperature 

 of the warm-blooded animals. The peroxides, however, are not capable 

 of transferring oxygen in unlimited quantities to disoxidizable sub- 

 stances, but as soon as a peroxide molecule has given off one atom of 

 oxygen, its oxidizing power is at an end. This difficulty can be over- 

 come in the following two ways: it is possible that new autoxidizable 

 substances are formed incessantly in the body; the second possibility 

 is the existence of a second class of oxidizing enzymes which act more 

 in the sense of true enzymes than the peroxides, inasmuch as they are 

 able to take up and give off oxygen indefinitely. Haemoglobin is 

 capable of binding and setting free oxygen indefinitely, but it is not 

 capable of transferring its oxygen to disoxidizable substances, and 

 hence does not act as an oxidase. 



The question of localization of the oxidizing enzyme in the cell was 

 raised by Spitzer.* He found that the proteins which can be extracted 

 from the cells do not possess the qualities of Jacquet's oxidase, but that 

 these qualities are found in such extracts as contain nucleoproteids. 

 The nucleoproteids are typical constituents of the cell nucleus, and 

 they differ from the proteins proper in that they contain PO 4 and Fe. 

 Spitzer was able to show, moreover, that of the products of cleavage 

 of nucleoproteids only those constituents were able to act as oxidases 

 which contained the Fe group. Two years ago I pointed out that if 

 Spitzer's researches are correct, the cell nucleus must be regarded as 

 the essential respiratory or oxidizing organ of the cell.f 



It is possible that we have two groups of oxidizing catalyzers in the 

 tissues : first, those of the type of peroxides which are possibly present 

 in the protoplasm; and second, substances which can act indefinitely 

 as oxidases, and are found in the nucleus. There are, indeed, a number 



* Spitzer, Pflitgtr's Archiv, Vol. 67, p. 615, 1897. 



t Loeb, Zeitsch. fur Entwickelungsmechanik, Vol. 8, p. 689, 1899. 



