M. Laborde, in attributing the secondary peripheric analgesia of intravenous or subcutaneous injections of hydrochlorate of Cocaine to the cerebral insusceptibility to pain, unconsciously made Cocaine a general anæsthetic.
Prof. Arloing (1885, Mémoire Soc. Biologie) has undertaken many experiments for demonstrating that Cocaine is not a general anæsthetic.
In his experiments, the learned physiologist of Lyons confirmed the results obtained by Vulpian as to the modifications occasioned by Cocaine of the arterial pressure; he saw, like his predecessors, the excito-medullary and convulsary effect of large doses of Cocaine and the increase of the salivary secretion, and in regard to its cerebro-spinal effect, he compared it to strychnine. General analgesia did not occur except from fatal doses or when accompanied by convulsions. The hydrochlorate of Cocaine, according to M. Arloing, produces and can produce nothing but local anæsthesia by temporarily changing the physical properties of the protoplasm of the terminal and fibrillary nervous elements easily accessible to medicinal agents in the cornea and mucous surfaces.
We will presently show that the several learned men who have been engaged in investigating the mechanism of action of the active principles of Coca were by no means in accord as regards the modus agendi of Cocaine in the production of local anæsthesia.
While M. Dujardin-Beaumetz likens the local anæsthetic action of Cocaine to that of cold, and while M. Laborde considers that it produces a diminished blood supply by the vaso-constrictor action of the great sympathetic nervous system, M. Arloing, on the contrary, explains it by a local action on the nervous protoplasm.
Moreover, in 1886, Schilling, a supporter of the vascular theory, advised inhalations of nine drops of nitrite of amyl, in three doses, inhalations which caused dilatation of the vessels, to revive patients poisoned with injections of Cocaine hydrochlorate.
In repeating these experiments in the laboratory, Dr. Laffont has succeeded little by little in enlarging his field of experiments, and finally has given to the Académie de Médecine (session of the 4th of January, 1888), a complete and definitive account of the action of the active principles of Coca on the different functions of the economy. This work of original researches and criticism of previous works will serve to explain the methodical and rational use of our preparations in the list of the different diseases where our former previsions had already led us to advise them.
In an earlier work (Comptes-rendus, Société de Biologie, Dec. 3, 1887), Dr. Laffont, studying the action of Cocaine on the great sympathetic nervous system, found that under the action of the active principle of Coca the functions of all the constrictor fibres of the great sympathetic nerve were increased.
The stomach contracts.