There are few opinions more popular than that which considers the speedy putrefaction of the body as the universal and never failing consequence of poisoning. To appreciate, however, the true value of such an indication, and to avoid the fallacies with which it is surrounded, it is essential to remember that the body of a person dying suddenly, and in what may be called full health, is very liable to run rapidly into a state of decomposition. As far, however, as our observations enable us to deduce any conclusion, certain vegetable poisons appear to accelerate such a change; for, very shortly after death, the body, under such circumstances, will frequently swell, become highly offensive, assume a black[193] appearance, and exhibit gangrenous spots on its surface. No such appearances, however, it is said, usually follow as the _specific_ consequence of the fatal operation of _mineral_ poisons; _Dr. Jaeger_ in an Inaugural dissertation,[194] which deserves to be better known, states, as the result of numerous experiments, that the putrefaction of animal bodies, poisoned by arsenic, whether buried or not, does not appear to be either unusually accelerated or retarded; and he moreover found that the generation of infusory animals, the production of larvæ and subterraneous vegetation, in and about the bodies of poisoned animals, took place as usual; and he remarked that “the immediate contact of an arsenical solution seemed, in several instances, to retard, in some degree, the putrefaction of the part to which it was applied in sufficient quantity.” In the extraordinary case examined by _Metzger_, in which the largest quantity of arsenic ever, perhaps, taken into the stomach, was found after death, the body was not opened until eighteen days after dissolution, and yet, says the anatomist, “_cadaver, quod mireris, sine ullo fœtore aut putredinis signo erat, ut et absque maculis lividis, si digitorum apices excipias_.” A case is also related by _Dr. Yelloly_,[195] in which death was occasioned by arsenic, but where not the slightest appearance of putrefaction was visible at the time of examination, which did not take place until forty-nine hours after death. On the other hand, _Morgagni_[196] states that, on dissecting a female who died from Arsenic, “_facies corporis posterior, ne suris quidem et calcibus exceptis, tota erat nigra_.” And in the interesting case of _William Mitchell_, as hereafter related, the appearance of the body appears to have indicated that decomposition had proceeded with more than ordinary celerity.