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ELEMENTS OF MATERIA MEDICA.

therefore, a matter of conjecture. Whatever it may be, it is probablyidentical with that which occurs during an epileptic paroxysm, and withthat produced by loss of blood: for the essential symptoms (insensibilityand convulsions occurring suddenly) are the same in all three states,—and ammonia has been found to relieve them (see p. 171). Dr. Hall{Led. on the Nerv. Syst. p. 139), has shewn that the convulsion fromhaemorrhage is spinal. Dr. Holst, Professor of Materia Medica in theUniversity of Christiana, Norway , told me of a case of epilepsy under hiscare, in which it was observed that the pulse in one arm was alwaysimperceptible during the paroxysm. On a post-mortem examination itwas discovered that an anomalous distribution of the arteries existed,—sothat this arm was supplied with blood which had circulated throughthe brain. Hence it would appear that during the epileptic paroxysmthe cerebral circulation was impeded. Does this happen in poisoningby hydrocyanic acid ?

(/.) Cause of death, —In most cases the immediate cause of death isobstruction of respiration. In some instances it is stoppage of theheart’s action. There are cases, however, in which the death is too im-mediate to be produced by obstructed respiration, while, on opening thechest, the heart is found still beating: this I have observed in experi-ments on rabbits with strong hydrocyanic acid.

(g.) Cumulative effects. —Hydrocyanic acid is not usually regarded asa cumulative poison; but a case mentioned by Dr. Baumgartner (quotedby Dr. Christison), as well as some other circumstances, seem to favourthe reverse opinion (see Dr. Christison’s Treatise ).

Uses. —We are indebted to the Italians (Borda, Brugnatelli, andRasori) for the introduction of hydrocyanic acid into the MateriaMedica. It was first employed by them at the commencement of thepresent century ; namely, from 1801 to 1806 (Granville, Treatise onHydrocyanic Acid , 2d ed. 1820).

(a.) Internal. —By the founders of the theory of contrastimulus thisacid was regarded as a powerful asthenic or contrastimulant, and, there-fore, as peculiarly useful in all diseases dependent on, or connected with,excitement. Hence it was employed in inflammatory affections. Butsubsequent experience has fully shewn that in these cases it possesseslittle or no remedial power.

In this country the reputation of hydrocyanic acid, as a medicinalagent, is chiefly founded on its effects in alleviating certain anomalousstomach complaints. It appears, from Dr. Granville’s statements (op. cit.),that laurel-water (which contains this acid) was used in these affectionsby Hufeland , Haller, Thuessen, Swediaur, and Sprengel, between theyears 1780 and 1796. But the first person who actually recommendshydrocyanic acid for them is Sprengel ( Pharmacologia ), in 1814. In1819, Dr. A. T. Thomson detailed a case, which led him to infer thatthis acid would be an important agent in the treatment of dyspepticaffections. But the profession are principally indebted to Dr. Elliotson (.Numerous Cases illustrative of the Efficacy of the Hydrocyanic Acid inAffections of the Stomach , 1820) for a full investigation of its powers inthese complaints.

Every practitioner is familiar with a stomach complaint in which painof a spasmodic character is the leading symptom, but which is not essen-tially accompanied by pyrexia, as in gastritis—by tendency to faint, as in