The narcotics chiefly employed in medicine are, opium, henbane, hemlock, etc. respecting which the reader will, in the order of the alphabet, find a concise account of the cases in which they may be used with advantage.
Whatever tends to induce stupor, ought to be carefully avoided, or at least very cautiously administered, in disorders of the stomnch and intestines ; for no other class of drugs is productive of such pernicious consequences to the nervous system. If taken in very small doses, narcotics at first excite and increase the action of the nerves, while they produce gentle undulations of the circulating blood ; but, in a larger proportion, they stimulate, and at length reduce or debilitate, all the nervous and muscular functions. Thus, their consequent effect is similar to that of wine, which, if used in moderation, promotes a temporary activity, by invigorating the nervous power, or rather, by causing an additional' motion (which in physic is called congestion) of the fluids towards the head; but, when drunk too freely, it weakens and stupifies all the sensitive organs, by the unusual pressure it causes on the brain Hence it will be readily inferred, that such heroic remedies can be prescribed with safety, by those only who are acquainted with the animal economy.