One of these possibilities is, that the _narcotic itself consumes the oxygen which activates living substance_ and uses it for its _individual_ oxydation, so that the specific oxydable material of living substance receives less oxygen from the oxygen carriers. Based on a series of interesting experiments this view has been recently maintained by _Bürker_.[224] He observed that with the electrolysis of acidulated water, to which a small per cent. of ether was added, a much less amount of oxygen was at the anode than in one used as means of control, containing acidulated water without ether. The oxygen was replaced at the anode by oxydation products of the ether, such as carbonic oxide, carbon dioxide, acetate aldehyde and acetic acid. In experiments with various narcotics he likewise found that the stronger the effect produced by narcosis, the greater the oxygen amount required for the oxydation taking place of electrolysis. _Bürker_ applies these results obtained for electrolysis to the processes in living substance and takes the view that the narcotic seizes on the active oxygen, and so withdraws it from the masses of living substance possessing a great oxygen requirement. It cannot be denied that this conception of the nature of certain narcotics deserves careful investigation. It seems to me, however, that before considering it in the light of a serious probability a grave difficulty would first have to be removed. In living substance the narcotic would occur under conditions essentially different from those existing during the experiment in the voltameter. In the former case there would be the struggle for oxygen of the specific oxydable cell masses to be met with. Considering the small amount of chemical activity of the greater number of narcotics it would appear at least doubtful if in this battle for supremacy the latter would achieve a victory. For some narcotics, as, for instance, carbon dioxide, this method of a depression of the oxydative processes would have no bearing whatever. This is rather to be looked for in the effects of oxydative suppression of the aldehydes, which _Warburg_[225] has recently observed and investigated. Here, however, it is not a true narcosis which is concerned. [224] _Bürker_: “Eine neue Theorie der Narkose.” Münchener Med. Wochenschrift, 1910. [225] _Warburg_: “Ueber Beeinflussung der Sauerstoffathmung. II Mitteilung. Eine Beziehung zur Constitution.” Zeitschr. f. physiolog. Chemie Bd. 71, 1911.