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 doubting whether such a combination of simultaneous, and in the present instance also consecutive symptoms, ever arise from natural causes. It is difficult to conceive a fortuitous concurrence of natural diseases producing at the same moment that variety and complexity of disorder which occur in the primary stage of the cases alluded to; and it would surely be a still more extraordinary combination which should farther add the supevention of epilepsy or partial palsy from a natural cause, at the exact period at which it appears as the secondary stage of poisoning with arsenic. All that any practitioner could say is, that a concurrence of the kind is within the bounds of possibility. He must be compelled to admit that it is in the highest degree improbable, and likewise that it could hardly take place from natural causes without the real causes of the symptoms being clearly indicated.

But to conclude, there are likewise collateral circumstances connected with the symptoms, which, taken along with the symptoms themselves, will sometimes place the fact of poisoning with arsenic beyond the reach of a doubt. Thus, if a person were taken several times ill with symptoms of general inflammation of the mucous membranes, after partaking each time of a suspected article of food or drink, the proof of the administration of arsenic would be very strong indeed; and it would be unimpeachable if at length a nervous affection succeeded at the usual period. Or above all, suppose several persons, who have partaken of the same dish, are seized about the same time with nearly the same symptoms of irritation of the mucous membranes. The proof of general poisoning would then be unequivocal. And if one or more of them should afterwards suffer from a nervous disorder, little hesitation ought to be felt in declaring that arsenic is the only poison which could have caused their complaints.

These views are of more practical consequence than may at first sight be thought. The doctrine which has been here espoused might have been applied to decide two criminal cases which at the time made a great noise in this country. One was the case of Eliza Fenning (p. 245). Here five persons were simultaneously attacked with symptoms, more or less violent, of inflammation of the whole alimentary canal; and in two of them epileptic convulsions appeared before the inflammatory symptoms departed. The other was the case of George Thom (p. 247). Here four persons were at one and the same time seized with the primary symptoms in an aggravated form; and in two of them, as these symptoms abated, obstinate partial palsy came on. On both trials, then, it might have been stated from the symptoms alone that poison had been given, and that arsenic was the only poison hitherto known to be capable of producing such effects.

In applying this doctrine to parallel instances two precautions must be attended to. On the one hand, care must be taken to ascertain, as may always be done, that the simultaneous symptoms of general irritation in the alimentary canal, arising soon after a meal, are not owing to unsound meat having been used in preparing it. And on