In poisoning by strychnine, the jaws are slightly, if at all, affected, trismus is a late symptom, and occurs only during a convulsive seizure.
In tetanus the result of disease, the locking of the jaws is an early and a marked symptom.
As death approaches the fits become more frequent, and the patient dies from exhaustion or suffocation.
Post-mortem Appearances.—There is no characteristic appearance found after death. The blood is fluid, the heart empty, with some congestion of the membranes of the brain. Absence of all cause for so violent and sudden a death. Rigor mortis is prolonged for some time.
Fatal Period.—The rapidity in the accession of the symptoms and fatal termination will, to some extent, depend upon the form in which the poison is taken—i.e. in solution or in pill. In most cases the symptoms appear in from three or four minutes to an hour or more after the poison is swallowed, death following in from ten minutes to six hours. As a rule, if the person lives for two hours after the onset of symptoms recovery may be expected.
Fig. 42.—Photo-micrograph of strychnine sulphate,
film preparation from chloroform solution, × 50.
(R. J. M. Buchanan.)
Fig. 43.—Photo-micrograph of
chromate of strychnine, × 50.
(R. J. M. Buchanan.)
Fatal Dose.—A quarter to half a grain; but large doses have been taken, followed by recovery.