THE PROCESSES OF DEPRESSION 259 



comes opaque and granulated, it appears darker than formerly 

 and in many cases displays a yellowish brown color in trans- 

 mitted light. Cells altered in this way no longer recover after 

 removal of the narcotic. These intense and rapidly appearing 

 alterations of protoplasm resulting from the application of 

 stronger doses of the narcotic can scarcely be explained as simply 

 the result of a mere decrease of the oxydative processes. They 

 would seem to consist rather, as suggested by Bins, as coagulation, 

 in an alteration of the state of certain components of living sub- 

 stance. Whether these alterations are already present in a corre- 

 spondingly slight amount in those degrees of narcosis after which 

 complete recovery can take place and further whether in this 

 case they are in any way concerned in bringing about the indi- 

 vidual symptoms of the former, are questions the decision of 

 which must be left to future investigations. Hober^ indeed 

 makes such an alteration of the colloidal state of the lipoid the 

 basis of a theory of narcosis. But such assumptions are scarcely 

 more than speculations. This is one of the points in which our 

 present knowledge is lacking. 



Even if we restrict ourselves to the actually established altera- 

 tions produced by the narcotic in living substance, new problems 

 present themselves, the investigation of which requires further 

 effort. Above all, the question arises as to the finer mechanism of 

 oxydative depression. In what manner does the narcotic mole- 

 cule, entering into the living substance, suppress the oxydative 

 processes ? Here there are very different possibilities to be taken 

 into consideration and up to the present in our investigations of a 

 suppression of the oxydative processes resulting from narcosis, 

 we have stood on the firm ground of assured facts. However, the 

 discussion of the nature of this suppression leads us into the 

 domain of hypothesis. But without hypothesis there can be no 

 progress in knowledge. In all branches of scientific research, 

 working hypotheses are required for the obtainment of new facts. 



On closer reflection, there are chiefly three possibilities, which, 



1 Hober: ''Beitrage zur physikalischen Chemie der Erregung und der Narkose." 

 Pflijgers Arch. Bd. 120, 1907. The same: "Die physikalisch-chemischen Vorgange der 

 Erregung." Sammelreferat. Zeitschr. f. allgem. Physiol. Bd. X, 1910. 



