68

ELEMENTS OF MATERIA MEDINA.

feebleness and irregularity of pulse, huntings, convulsions, and insensi-bility. Tobacco is remarkable for producing excessive feebleness of tliemuscular system. Foxglove sometimes causes salivation. Both sub-stances have been employed to reduce the frequency and force of the ;<heart’s action, and to cause diuresis; tobacco has been used as a 'purgative in hernia and intus-susception. ;

h. The eighth group contains certain metallic preparations which act jspecifically on the nervous system, such as the preparations of arsenic, |bismuth, copper, silver, and zinc. Their local action is irritant orcaustic. Their influence over the cerebro-spinal system is shown by jtheir remedial power in some disorders of this system, as epilepsy and ichorea (in consequence of which they have been termed antispasmodics), ;and by the giddiness, cramps or convulsions, paralysis, coma, &c. whentaken in poisonous quantities. In small doses they are considered to actas tonics, principally on account of their beneficial agency in periodicaldiseases, especially ague. This group corresponds very nearly to thatcalled by Vogt, nervino-alterantia.

i. The ninth group contains the plumbeous preparations, which areremarkable for producing colic and paralysis. These compounds areusually called astringents.

k. The tenth group is formed to include mercurial compounds, whichby long-continued action in small quantities, cause a convulsive move- ■ment of the muscles ( tremor mercurialis ) as in chorea. S

Notwithstanding the numerous groups or subdivisions of the class tcerebro-spinants, which I have thought it necessary to make, more Jprobably ought to be added. If, as Dr. Hall believes, the tone of the |muscular system is derived from the true spinal system, the substances 1called tonics should form a group of cerebro-spinants rather than a Idistinct class. Moreover, the medicines known as antispasmodics (such |as asafcetida) ought perhaps to be placed in this class, on account of jtheir remarkable influence in hysteria and infantile convulsions. |

Cause or mode of death. —The immediate cause or mode of death from jthe use of cerebro-spinants is not always the same,—in some instances jit is an affection of the respiratory organs, in others of the heart.

a. Paralysis of the muscles of respiration. — In some cases therespiratory muscles do not receive their proper supply of nervous Ienergy', in consequence of which respiration is performed with in-creasing difficulty, until, ultimately, asphyxia is produced. This kindof death is caused by opium, and sometimes by dilute hydrocyanicacid. Before the cessation of life we observe the breathing to becomelaborious or even stertorous, as in cases of apoplexy ; and if the body beopened immediately after death, the heart is found beating, oftentimeswith considerable force and for some minutes. These are the cases inwhich it has been proposed to prolong life by artificial respiration untilthe cerebral disorder has passed off. The proposition is not supportedmerely by its ingeniousness and plausibility, but by experience. Thefollowing is a case in point related by Mr. Whateley, and quoted byDr. Christison ( Treatise on Poisons, p. 680, 3d ed.) A middle-agedman swallowed half an ounce of crude opium, and soon became lethargic.He was roused from this state by appropriate remedies, and his surgeonleft him. But the poison not having been sufficiently^ discharged, he fellagain into a state of stupor; and when the surgeon returned, he found