INTRODUCTION. 6 



appearance of nitrates in consequence of an oxidation of nitrogen 

 in cases of putrefaction, which process is ordinarily explained by 

 the statement that, in putrefaction, reducing, easily-oxidizable 

 bodies are formed which split oxygen molecules, liberating oxygen 

 atoms which afterward oxidize the nitrogen. It is assumed also that 

 the cells of the animal tissues and organs, like these lower organ- 

 isms, which cause fermentation and putrefaction, undergo such 

 splitting processes in which easily-oxidizable substances, perhaps 

 also hydrogen in statu nascendi (HOPPE-SEYLER), are produced. 

 The observations of EHRLICH, that certain blue coloring matters 

 alizarin blue and indophenol blue are decolorized by the tissues of 

 the living animal and become blue again on exposure to air, seem 

 also to be a proof of the occurrence of easily-oxidizable combina- 

 tions in the tissues. A further proof of this is found in the obser- 

 vations of C. LUDWIG and ALEX. SCHMIDT that in the blood of 

 asphyxiated animals, as well as in the absence of oxygen, an accu- 

 mulation of reducing, easily-oxidizing substances takes place. 



In accordance with what has been above stated, we may assume 

 that the oxidation in the animal body takes place in the following 

 manner: The forces peculiar to protoplasm, jinknown to us, but 

 acting similarly to heat, increase the intramolecular movements of 

 the atoms in such a. way that a loosening or splitting of the 

 molecule occurs and an aggregation of the oxygen is made possible 

 ("primary oxidation/' NASSE). The new products formed in this 

 manner may perhaps in part be in direct combination with neutral 

 oxygen (" direct oxidation/' NASSE) and gradually burned within 

 the body, but they must probably first undergo a further splitting, 

 and then succumb to consecutive oxidation, until, after repeated 

 splitting and oxidation, the final products of the exchange of 

 material are formed. Finally, the easily-oxidizable products of 

 decomposition, when they split the oxygen molecule and only 

 combine with one of the oxygen atoms, may act on difficultly- 

 oxidizable substances in an indirect or, as NASSE has called it, a 

 "secondary oxidation" by the setting free of the second atom. 



Thus the oxidation within the animal body is caused by the 

 action of forces acting similarly to heat, which loosens or splits the 

 molecules; and since this oxidation has long been known as com- 

 bustion, this view is easily reconcilable with the mode of action 



UFITBRSITT 



