carried out with alcohol, ether, chloroform and also carbon dioxide. His experiments have shown in the most uniform manner that, in spite of the requirement of oxygen by the centers being increased to its highest extent, and notwithstanding the most ample oxygen supply during narcosis, after cessation of the same and the introduction of an oxygen-free saline solution _no trace of recovery occurred_, whereas after a supply of oxygen was introduced tetanic contractions reappeared at once. _During narcosis, therefore, the centers, in spite of their great requirement of oxygen, lose their capability of oxydative splitting up and consumption of oxygen._ [206] _H. Winterstein_: “Zur Kenntniss der Narkose.” Zeitschr. für allgem. Physiol. Bd. I, 1902. After the methods for asphyxiation of the _nerve_ had been worked out and perfected the wish arose likewise to carry out for these structures an analogous series of experiments to that employed for the centers and based on the same chain of reasoning. These investigations have the advantage of essentially simpler conditions. After having convinced myself by experiments, that the results on the nerve were in complete conformity with those on the spinal cord, at my suggestion _Fröhlich_[207] repeated and continued these experiments on a more extended scale. A nerve was asphyxiated by the previously described method. This is accomplished in the simplest manner by the opening or closing of stop cocks in the apparatus I have employed which permit of pure nitrogen, or nitrogen with ether, and finally also oxygen with ether or pure oxygen being conducted at will through the glass chamber. If the nerve was so far depressed in pure nitrogen that conductivity became obliterated for about two cm. of the asphyxiated stretch, it was then narcotized in nitrogen. Following this oxygen with ether was supplied for a time. Then the oxygen-ether mixture was displaced by one of nitrogen and ether and finally by pure nitrogen. Even after a prolonged period, a recovery in pure nitrogen never took place. On the other hand, the nerve recovered at once, as soon as oxygen without ether was introduced. The results of these investigations are, therefore, completely in harmony with those undertaken by _Winterstein_ on the nervous centers. They were later likewise entirely confirmed by similar experiments of _Heaton_.[208] All these investigations furnished the proof _that in narcosis, living substance, notwithstanding even the greatest oxygen deficiency, is not capable of producing oxydation, neither can consumption of oxygen take place, with which, after cessation of the narcosis, oxydative splitting up can be carried out_. [207] _Fr. W. Fröhlich_: “Zur Kenntniss der Narkose des Nerven.” Zeitschr. f. allgem. Physiol. Bd. III, 1904. [208] _Trevor B. Heaton_: “Zur Kenntniss der Narkose.” Zeitschr. f. allgem. Physiol. Bo. 1910.