the dose was seven drachms, and death took place in nine hours. M. Devergie has related a similar case of poisoning with the sulphuret, where the symptoms did not begin for three hours; and here too the patient fell asleep immediately after swallowing the poison.[607] Professor Orfila has noticed an instance, to be quoted afterwards, where there appears to have been scarcely any symptom at all for five hours[608] (p. 243). I suspect we must also consider as an instance of the same kind the case which gave occasion to the trial of Mrs. Smith here in 1827. A white draught was administered in a suspicious manner at ten in the evening; the girl immediately went to bed; and no symptoms appeared till six next morning, from which time her illness went on uninterruptedly.[609] In three of the preceding cases it will be remarked that sleep intervened between the taking of the poison and the invasion of the symptoms; and it is therefore not improbable that the reason of the retardation is the comparative inactivity of the animal system during sleep.—In voluntary poisoning, as in a case related by Dr. Roget, a slight attack of sickness or vomiting occasionally ensues immediately after solid arsenic is swallowed, and some time before the symptoms commence regularly.[610] The observations now made will often prove important for deciding accusations of poisoning; for pointed evidence may be derived from the commencement of the symptoms, after a suspected meal, corresponding or not corresponding with the interval which is known to elapse in ascertained cases. The reader will see the effect of such evidence in attaching guilt to the prisoner in the case of Margaret Wishart, which I have detailed elsewhere.[611] In the trial of Mrs. Smith, the want of the correspondence just mentioned contributed greatly to her acquittal; for the symptoms of poisoning did not begin till more than eight hours after the only occasion on which the prisoner was proved to have administered any thing in a suspicious manner. As I was not at the time acquainted with any parallel case except that recorded by Orfila, I hesitated to ascribe the symptoms to the draught; and consequently, as the other medical witnesses felt the same hesitation on the same account, the proof of administration was considered to have failed. I am not sure that I should have now felt the same difficulty. The intervening state of sleep probably affords an explanation of the long interval; and the cases noticed by Mr. Macaulay and M. Devergie are parallel, though the interval in them was certainly not so great.—There is a limit, however, to the possible interval in such cases. It seems impossible that the action of the poison shall be suspended for three entire days. Yet death has been ascribed to arsenic in such circumstances. A child 3½ years old having swallowed eight grains with bread and butter, but being soon made to vomit forcibly by emetics,