In both cases recovery could only be brought about by an introduction of oxygen. From the sum of all these experiments it results that during narcosis in air the nerve, even when a sufficiency of oxygen is present, gradually asphyxiates and loses its capability of conduction, and this in about the same length of time as the other nerve in pure nitrogen. These investigations furnish two important facts for the theory of narcosis. First, that in narcosis living substance becomes asphyxiated notwithstanding the presence of an ample oxygen supply, and secondly, that asphyxiation occurs in the same time, or somewhat more rapidly, in pure nitrogen under otherwise similar conditions than without narcosis. In other words, it is shown that the breaking down processes of metabolism continue in narcosis as anoxydative disintegration. _In narcosis, therefore, asphyxiation takes place with approximately the same or a somewhat greater rapidity than that in an oxygen-free medium._ The fact here established explains in the simplest manner the often described observation that in the human being and in mammals during prolonged anæsthesia typical products of insufficient combustion, such as fatty acids, lactic acid and above all aceton, in not inconsiderable quantities are eliminated, as the case may be, by the urine or the respiratory air.[216] If, as has been shown by the foregoing experiments, the processes of disintegration can continue to anoxydatively take place during narcosis, the problem arises, if this anoxydative breaking down can be further increased by excitating stimuli. This question has been answered likewise by means of experiments on the nerve made by _Heaton_.[217] The two sciatic nerves of the same frog were drawn through a double glass chamber of the form previously described so that each nerve lay on an electrode and with the central stump protruding out of the chamber hanging likewise over an electrode. As in the former instances the muscle contraction of the shank again served as indicator. Both nerves were then subjected to the same current of nitrogen-ether. When, as a result of the narcosis, their irritability has sunk to the level of “stromschleifen” the central stump of the one nerve was continuously stimulated with faradic shocks during a prolonged period, while the other nerve remained at rest. Finally, by displacement of the current of nitrogen-ether with one of pure nitrogen, cessation of narcosis was brought about. It was then seen that the irritability of the continuously stimulated nerve showed a much greater decrease than that of the nonstimulated. The control made by introduction of air demonstrated that both nerves recovered in an oxygen supply. _There can, therefore, be no doubt, by comparative experiments we find, that during narcosis anoxydative disintegration can be still further increased by the action of stimuli._